2017 Padma Awads

Padma Awards - one of the highest civilian Awards of the country, are conferred in three categories, namely, Padma Vibhushan, Padma Bhushan and Padma Shri.
📌 The Awards are given in various disciplines/ fields of activities, viz.- art, social work, public affairs, science and engineering, trade and industry, medicine, literature and education, sports, civil service, etc. ‘Padma Vibhushan’ is awarded for exceptional and distinguished service; ‘Padma Bhushan’ for distinguished service of high order and ‘Padma Shri’ for distinguished service in any field.
📌 The awards are announced on the occasion of Republic Day every year.
📌 These awards are conferred by the President of India at ceremonial functions which are held at Rashtrapati Bhawan usually around March/ April every year.
📌 This year the President of India has approved conferment of Padma Awards to 89 persons.
📌 The list comprises of 7 Padma Vibhushan, 7 Padma Bhushan and 75 Padma Shri Awardees. 
📌 19 of the awardees are women and the list also includes 5 persons from the category of foreigners, NRIs, PIOs and 6 Posthumous awardees.
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🇮🇳🇮🇳🇮🇳 PADMA VIBHUSHAN 🇮🇳🇮🇳🇮🇳
✔ Name▶▶▶Field ▶▶▶State ✔
Shri K J Yesudas ➡ Art-Music ➡ Kerala
Sadhguru Jaggi Vasudev ➡ Others-Spiritualism ➡ Tamil Nadu
Shri Sharad Pawar ➡ Public Affairs ➡ Maharashtra
Shri Murli Manohar Joshi ➡ Public Affairs ➡ Uttar Pradesh
Prof. Udipi Ramachandra Rao ➡ Science & Engineering ➡ Karnataka
Late Shri Sunder Lal Patwa (Posthumous) ➡ Public Affairs ➡ Madhya Pradesh            
Late Shri PA Sangma (Posthumous) ➡ Public Affairs ➡ Meghalaya
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🇮🇳🇮🇳🇮🇳 Padma Bhushan 🇮🇳🇮🇳🇮🇳
✔ Name▶▶▶Field ▶▶▶State ✔
              
Shri Vishwa Mohan Bhatt ➡ Art-Music ➡ Rajasthan
Prof. (Dr.) Devi Prasad Dwivedi ➡ Literature & Education ➡ Uttar Pradesh          
Shri Tehemton Udwadia ➡ Medicine ➡ Maharashtra
Shri Ratna Sundar Maharaj ➡ Others-Spiritualism ➡ Gujarat
Swami Niranjana Nanda Saraswati ➡ Others-Yoga ➡ Bihar
H.R.H. Princess Maha Chakri Sirindhorn (Foreigner) ➡ Literature & Education ➡ Thailand
Late Shri Cho Ramaswamy (Posthumous) ➡ Literature & Education –Journalism ➡ Tamil Nadu
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🇮🇳🇮🇳🇮🇳 Padma Shri 🇮🇳🇮🇳🇮🇳
✔ Name▶▶▶Field ▶▶▶State ✔
Smt. Basanti Bisht ➡ Art-Music ➡  Uttarakhand          
Shri Chemanchery Kunhiraman Nair ➡ Art-Dance ➡ Kerala
           
Smt. Aruna Mohanty ➡ Art-Dance ➡ Odisha
Smt. Bharathi Vishnuvardhan ➡ Art-Cinema ➡ Karnataka
Shri Sadhu Meher ➡ Art-Cinema ➡ Odisha
Shri T K Murthy ➡ Art-Music ➡ Tamil Nadu
Shri Laishram Birendrakumar Singh ➡ Art-Music ➡ Manipur
Shri Krishna Ram Chaudhary ➡ Art-Music ➡ Uttar Pradesh
Smt. Baoa Devi➡Art-Painting ➡Bihar
Shri Tilak Gitai➡Art-Painting ➡Rajasthan
Dr. Prof. Aekka Yadagiri Rao➡Art-Sculpture ➡Telangana
Shri Jitendra Haripal➡Art-Music ➡Odisha
Shri Kailash Kher➡Art-Music ➡Maharashtra
Smt. Parassala B Ponnammal➡Art-Music ➡Kerala
Smt. Sukri Bommagowda➡Art-Music ➡Karnataka
Shri Mukund Nayak➡Art-Music ➡Jharkhand
Shri Purushottam Upadhyay➡Art-Music ➡Gujarat
Smt. Anuradha Paudwal➡Art-Music ➡Maharashtra
Shri Wareppa Naba Nil➡Art-Theatre ➡Manipur
Shri Tripuraneni Hanuman Chowdary➡Civil Service➡Telangana
Shri T.K. Viswanathan➡Civil Service➡Haryana
Shri Kanwal Sibal➡Civil Service➡Delhi
Shri Birkha Bahadur Limboo Muringla➡Literature & Education➡Sikkim
Smt. Eli Ahmed➡Literature & Education➡Assam
Dr. Narendra Kohli➡Literature & Education➡Delhi
Prof. G. Venkatasubbiah➡Literature & Education ➡Karnataka
Shri Akkitham Achyuthan Namboothiri➡Literature & Education➡Kerala
Shri Kashi Nath Pandita➡Literature & Education➡Jammu & Kashmir
Shri Chamu Krishna Shastry➡Literature & Education➡Delhi
Shri Harihar Kripalu Tripathi➡Literature & Education➡Uttar Pradesh
Shri Michel Danino➡Literature & Education➡Tamil Nadu
Shri Punam Suri➡Literature & Education➡Delhi
Shri VG Patel➡Literature & Education➡Gujarat
Smt. V Koteswaramma➡Literature & Education➡Andhra Pradesh
Shri Balbir Dutt➡Literature & Education-Journalism➡Jharkhand
Smt. Bhawana Somaaya➡Literature & Education-Journalism➡Maharashtra
Shri Vishnu Pandya➡Literature & Education-Journalism➡Gujarat
Dr. Subroto Das➡Medicine ➡Gujarat
Dr. (Smt.) Bhakti Yadav➡Medicine ➡Madhya Pradesh
Dr. Mohammed Abdul Waheed➡Medicine ➡Telangana
Dr. Madan Madhav Godbole➡Medicine ➡Uttar Pradesh
Dr. Devendra Dayabhai Patel➡Medicine ➡Gujarat
Prof. Harkishan Singh➡Medicine ➡Chandigarh
Dr. Mukut Minz➡Medicine ➡Chandigarh
Shri Arun Kumar Sharma➡Others-Archaeology ➡Chhattisgarh
Shri Sanjeev Kapoor➡Others-Culinary ➡Maharashtra
Smt. Meenakshi Amma➡Others-Martial Art➡Kerala
Shri Genabhai Dargabhai Patel➡Others-Agriculture ➡Gujarat
Shri Chandrakant Pithawa➡Science & Engineering➡Telangana
Prof. Ajoy Kumar Ray➡Science & Engineering➡West Bengal
Shri Chintakindi Mallesham➡Science & Engineering➡Andhra Pradesh
Shri Jitendra Nath Goswami➡Science & Engineering➡Assam
Shri Daripalli Ramaiah➡Social Work➡Telangana
Shri Girish Bhardwaj➡Social Work ➡ Karnataka
Shri Karimul Hak➡Social Work➡West Bengal
Shri Bipin Ganatra➡Social Work➡West Bengal
Smt. Nivedita Raghunath Bhide➡Social work➡Tamil Nadu
Shri Appasaheb Dharmadhikari➡Social Work➡Maharashtra
Baba Balbir Singh Seechewal➡Social Work➡Punjab
Shri Virat Kohli➡Sports-Cricket ➡Delhi
Shri Shekar Naik➡Sports-Cricket ➡Karnataka
Shri Vikasa Gowda➡Sports-Discus Throw➡Karnataka
Smt. Deepa Malik➡Sports-Athletics ➡Haryana
Shri Mariyappan Thangavelu➡Sports-Athletics ➡Tamil Nadu
Smt. Dipa Karmakar➡Sports-Gymnastics ➡Tripura
Shri P R Shreejesh➡Sports-Hockey ➡Kerala
Smt. Sakshi Malik➡Sports-Wrestling ➡Haryana
Shri Mohan Reddy Venkatrama Bodanapu➡Trade & Industry➡Telangana
Shri Imrat Khan(NRI/PIO)➡Art-Music ➡USA
Shri Anant Agarwal(NRI/PIO)➡Literature & Education➡USA
Shri H.R. Shah(NRI/PIO)➡Literature & Education-Journalism➡USA
Late (Smt.) Suniti Solomon(Posthumous)➡Medicine ➡Tamil Nadu
Shri Asoke Kumar Bhattacharyya(Posthumous)➡Others-Archaeology ➡West Bengal
Dr. Mapuskar(Posthumous)➡Social Work➡Maharashtra
Smt. Anuradha Koirala (Foreigner)➡Social Work➡Nepal

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Biology

Deoxyribo nucleic Acid (DNA) :

• DNA stands for Deoxyribo nucleic Acid , it was discovered by Frederic Maischer.
• DNA is a double stranded molecule made up of elongated chain of sub-units called nucleotides.
• DNA is mainly found in nucleus and in small amount it is also found in mitochondria an chloroplast.
• Chemically a nucleotide has three components.

(1) Nitrogenous base
(2) Pentose Sugar
(3) Phosphate group.

• Nitrogenous  base are of two type i.e.Purine & Pyrimidines. 
• Purines contain two nitrogen base i.e. Adinine and Guanine.
• Pyrimidine nitrogen base are Thymine and Cytosine, thus there are four kinds of nucleotide present in DNA i.e. Adinine, Guanine, Thymine, Cytosine.

Structure of DNA:

• Watson and Crick give the structural model of DN
• DNA molecule is consists of two polynucleotide strand, forming a double helix structure.
• Each strand has a backbone of sugar and phosphate, nitrogen base is attached to the sugar.
• Two strands are joined together by hydrogen bonds between the bases.
• Adenine pairs with thymine whereas guanine pairs with cytosine.
• Adenine and thymine are complementary to each other and cytosine is complementary to guanine.

Function of DNA:

• DNA is genetic material and contains genetic information in coded form.
• DNA has two main function replication and expression.

2.Ribonucleic Acid (RNA) : 

• RNA stands for Ribonucleic acid.
• RNA is single stranded nucleic acid made up of phosphate, ribose sugar and nitrogen base uracil, adinine, guanine and cytosine.
• It is found in nucleus as well as cytoplasm.
• Its main function is to synthesis the protein.
• RNA is of three kind.

    1.Messenger RNA (mRNA): It brings the massage from DNA found in the nucleus to cytoplasm in the coded          form.
     2.Ribosomal RNA (rRNA): Present in ribosome which is the site of protein synthesis.
     3.Transfer RNA (t RNA): It is the carrier of amino acid and transfers it to the ribosome.
Difference between RNA and DNA

3.Virus:

• Virus was discovered by Russian Scientist Iavanosky during the test of Mosaic disease in Tobacco.
• Virus acts as a link between the living and non-living.
• Virus is dead but when it comes in contact with the living cell it gets activated.
• ‘The virus in which RNA  is found as the genetic material are called Retrovirus.
• Virus is of three types:

1. Plant Virus: RNA is present as its nucleic acid
2. Animal Cell: DNA and sometimes RNA is found in it.
3. Bacteriophage: They kill the bacteria e.g. T-2 phage.

4.Bacteria:

• Bacteria was discovered by Antony von Lecuwenhoek and its study is known as bacteriology.
•  Bacteria is of different types on the basis of shape:

1. Bacillus: This is a rod like or cylindrical.
2. Round or Cocus: These are round and smallest bacteria.
3. Comma shape or vibrio
4. Sprillum: Spring or Screw shaped.

• Anabaena and Nostoc cyanobacteria fixed the atmospheric nitrogen into soil.

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Optics

 

LIGHT

• Light is a form of energy, which is propagated as electromagnetic wave.
• It is the radiation which make our eyes able to 'see the object. Its speed is 3 x 108 m/s. It is the form of energy. It is a transverse wave.
• It takes 8 min 19s to reach on the earth from the sun and the light reflected from moon takes 28s to reach earth.
• When light falls on the surface of an object it can either be

1. Absorbed - If an object absorbs all the light falling on it , then it will appear perfectly black for example a blackboard
2. Transmitted - An object is said to transmit light if it allows light to pass through itself and such objects are transparent.
3. Reflected - If an object sends back light rays falling on its surface then it is said to have reflected the light

Reflection of Light

• When a ray of light falls on a boundary separating two media comes back into the same media, then this phenomenon is called reflection of light.

Laws of Reflection of light

1. The angle of incidence is equal to the angle of reflection, and
2. The incident ray, the reflected ray and the normal to the mirror at the point of incidence all lie in the same plane.

Reflection from Plane Mirror

• If an object moves towards a plane mirror with speed v, relative to the object the moves towards it with a speed 2v.
• To see his full image in a plane mirror, a person required a mirror of at least half of his height.

Refraction of Light

• The phenomenon of deviation of light rays from its path when it travels from one transparent medium to another medium is called refraction of light.
• The cause of refraction is due to the different speed of light in different medium.
• When a ray of light enters from one medium to other medium, its frequency and phase do not change, but wavelength and velocity change.
• Due to refraction form Earth's atmosphere, the stars appear to twinkle.

Laws  of Refraction:

• The incident ray, the refracted ray and the normal at the point of incidence all three lie in the same plane.
• The ratio of sine of angle of incidence to the sine of angle of refraction remains constant for a pair  of media i.e.

Sin i/Sin r  = constant=μ2/μ1,  this law is known as snell's law

Application of Refraction:

• When light travels from a denser medium towards  a rarer medium it deviates away from the normal , therefore a pond appear shallower.
• A coin appears at lesser depth in water.
• Writing on a paper appears lifted when a glass slab is placed over paper.

Critical Angle:

• The angle of incidence in a denser medium for which the angle of refraction in rarer medium becomes 90°, is called the critical angle.

Total Internal Reflection:

When a light ray travelling from a denser medium to the rarer medium is incident at the interface at an angle of incidence greater than critical angel, then light rays reflected back into the denser medium , this phenomenon is known as total internal reflection
Sparkling of diamond, mirage and looming, shinning of air bubble in water and optical Fibre are examples of total internal reflection.

Spherical Mirror:

Spherical mirror are of two types

1. Concave mirror
2. Convex mirror

• Image formed by a convex mirror is always virtual, erect and diminished.
• Image formed by a concave mirror is generally real and inverted.

Uses of Concave Mirror

• As a shaving mirror
• As a reflector for the head lights of a vehicle, search light
• In ophthalmoscope to examine eye, ear, nose by doctors.
• In solar cookers.

Uses of Convex Mirror

• As a rear view mirror in vehicle because it provides the maximum rear field of view and image formed is always erect.
• In sodium reflector lamp.

Important points related to spherical Mirrors:
Centre of Curvature (c): The centre of the hollow glass sphere of which the mirror is a part.
Radius of Curvature(R): The radius hollow sphere of which the mirror is a part.
Pole(P): The mid-point of a spherical mirror is called pole.
Focus (F): when a parallel beam of light rays is incident on a spherical mirror then after reflection it meets or appears to meet at a point on principal axis, called focus of the spherical mirror.
Focal length(f): 
Focal length d= R/2

Lenses :

A lens is a uniform refracting medium bounded by two spherical surface or one plane surface.

Lenses are of two types:

• Convex lens
• Concave lens

Prism :

Prism is a uniform transparent refracting medium bounded by plane surfaces inclined at some angles forming a triangular shape.
Dispersion of light:
When a light is incident on a glass prism, it splits into its seven colour comonents in the following sequence VIBGYOR,  and this is known as dispersion of white light.
The refractive index of glass is maximum for violet colour and minimum for red colour of light, therefore violet colour of light deviated maximum and red colour of light deviated least.

 

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Motion

Scalar Quantities: 

 Physical quantities which have magnitude only and no direction are called scalar quantities.
Example: Mass, speed, volume, work, time, power, energy etc.

Vector Quantities: 

Physical quantities which have magnitude and direction both and which obey triangle law are called vector quantities.
Example: Displacement, velocity, acceleration, force, momentum, torque etc.
Electric current, though has a direction, is a scalar quantity because it does not obey triangle law.
Moment of inertia, pressure, refractive index, stress are tensor quantities.

Distance: 

Distance is the actual path traveled  by a body in a given period of time.

Displacement:

• The change in the position of the object in a given period of time
•  Distance is a scalar quantity whereas displacement is a vector quantity both having the same unit (metre)
•  Displacement may be positive, negative or zero whereas distance is always positive.

Speed:

• Distance travelled by the moving object in unit time interval is called speed i.e. speed = Distance/ Time
• It is a scalar quantity and its SI unit is metre/second (m/s).
• Speed of an object at any instant is called instantaneous speed.
• An object is said to be traveled with non-uniform speed if it covers unequal distance in equal interval of time.

Velocity:

•  Velocity of a moving object is defined as the displacement of the object in unit time interval i.e., velocity =
• It is a vector quantity and its SI unit is metre/second.
• If a body goes equal displacement in equal interval of time then it is called uniform velocity.
• If a body undergoes unequal displacement in equal interval of time then it is called variable velocity.

Relative velocity
= V₁ +V₂ if two travels in opposite direction
=V₁-V₂ if two travels in same direction

Acceleration:

• Acceleration of an object is defined as the rate of change of velocity of the object .
• It is a vector quantity and its SI units is metre/second² (m/s²)
• If velocity decreases with time then acceleration is negative and is called retardation.
• If acceleration does not change with time it is called constant acceleration.
• Some equation of acceleration;

          V=u+at
         S=ut+at²/2
        V²= u²+2as
Here v=final velocity, u is initial velocity, t is time ineterval, a is acceleration and s is the distance travel.

Circular Motion:

• The motion of an object along a circular path it is called circular motion.
• If the object moves with uniform speed, its motion is uniform circular motion.
• Uniform circular motion is an accelerated motion because the direction of velocity changes continuously.

Angular Displacement and Velocity:

The angle subtended at the centre of a circle by a body moving along the circumference of the circle is called angular displacement of the body. It unit is radian.
Angular displacement= length of arc/radius of circle
Time rate of change of angular displacement is called angular velocity.
It is generally denoted by ω and 

Force:

• Force is that external cause which when acts on a body changes or tries to change the initial state of the body.
• Its SI unit is Newton(N).
• A body is said to be in equilibrium if the sum of all the forces acts on the body is Zero.
• Nuclear force is the strongest force.

Momentum:

•  Momentum is the property of a moving body and is defined as the product of mass and velocity of the body i.e.
•           Momentum = mass x velocity.
• It is a vector quantity. Its SI unit is kgm/s.

Newton’s Law:

Newton first law

If no external force acts on a body then it remains in the same state of rest or motion that is in its present state.

Inertia of Rest:

• Inertia is the property of a body by virtue of which it opposes any change in its state of rest or of uniform motion.
• When a bus or train at rest starts to move suddenly the passengers sitting in it feels jerk in backward direction due to inertia of rest.
• Dust particle come out of a carpet if we beat it with stick.
• A passenger jumping out of a train is advised to jump in the direction of bus and ran for a short distance.

Inertia of Motion:

When a running bus or train stops suddenly, the passengers sitting in it jerk in forward direction due to inertia of motion.

Newton's second law of motion:

• The rate of change in momentum of a body is directly proportional to the applied force on the body and takes place in the direction of force.

If F = force applied, a = acceleration produced and m = mass of body
then F = ma.

Newton's Third Law of Motion : 

To every action, there is an equal and opposite reaction.
Examples of third law –

• Recoil of a gun
• Motion of rocket
• While drawing water from the well, if the string breaks up the man drawing water falls back.

Centripetal Force:
When a body is in circular motion, a force always acts on the body towards the centre of the circular path, this force is called centripiatl force
If a body of mass m is moving on a circular path of radius R with uniform speed v, then the required centripetal force

Centrifugal Force:

• Centrifugal force is such a pseudo force.
• It is equal and opposite to centripetal force.

Application of centripetal and Centrifugal forces:

• Roads are banked at turns to provide required centripetal force for taking a turm.
• Cream is separated form milk when it is rotated in a vessel about the same axis.
• Gravitational force of attraction between earth and sun acts as centripetal force.
• Orbital motion of electrons around the nucleus
• Cyclist inclined itself from vertical to obtain required centripetal force.

Principle of conservation of linear momentum:

• If no external force acts on a system of bodies, the total linear momentum of the system of bodies remains constant.
• As a consequence, the total momentum of bodies before and after collision remains the same.
• As in case of rocket, ejecting gas exerts a forward force which helps in accelerating the rocket in forward direction.

Impulse:

• When a large force acts on a body for very small time, then force is called impulsive force.
• Impulse is defined as the product of force and time.
• Impulse = force x time = change in momentum.
• It is a vector quantity and its direction is the direction of force. Its SI unit is newton second (Ns).

Friction:

It is force which acts on a body when two body are in contact and one tries to move over other.
Types of Friction:
Static Friction:
The opposing force which acts on acts on a body when it tries to move over the other but actual motion has yet not started.
Limiting friction:
It is the force that comes to play, when a body is at the verge of moving over the other body.
Kinetic Friction:
This is the opposing force that comes to play when one body actually moves over the surface of another body is called kinetic friction. It is of two types which are as follows:
Sliding Friction: When a body slides over the surface of other
Rolling Friction: When a body rolls over the surface of another body

• It is easier to roll a body than to slide because the sliding friction is greater than the rolling friction.
• It is easy to drive a bicycle when its  tyres are fully inflated because it decreases rolling friction.

Application of Friction:

• A ball bearing is used to reduce the rotational friction.
• Friction is necessary for walking and to apply breaks in vehicles.
• When a pedal is applied to a bicycle, the force of friction on rear wheel is in forward direction and on front wheel it is in the backward direction.
• Friction can be reduced by applying the polishing or applying any lubricants.
• The tyre are made up of synthetic rubber because its coefficient of friction with road is larger and stops sliding the bicycle.

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Gravitation and Satellite

Gravitation:

Each and every massive body attracts each other by virtue of their masses. This phenomenon is called gravitation.

Newton’s law of Gravitation.

The gravitational force of attraction between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
Gravitational force (F)=Gm1m2/ r ²

• Where G is the gravitational constant its value is 6.67×10^-11 Nm²kg^-2.
• m1, m2 are the mass of two bodies and r is the distance between them.
• Gravitational force is central as well as conservative force.

Acceleration Due to Gravity of Earth:

• The acceleration produced in a body due to the gravitational pull of earth is called acceleration due to gravity.

g=GM/R²  where M is the mass of earth and R is the radius of earth.

• The value of g changes slightly changes from place to place but its value near the earth’s surface is 9.8ms^-2.
• Gravitational force is the weakest force in nature.

Condition affecting the value of g:

• Shape of Earth: Earth shape also affect the value of acceleration due to gravity that’s why g is maximum at poles and minimum at the equator.
• Rotation of Earth on its axis:
• Effects of Altitude: The value of g decreases with the increase in height.
• Effects of depth: The value of g decreases with depth and become zero at the centre earth.

Mass and Weight:

• The mass of a body is the quantity of matter contains in it and it is a scalar quantity and its SI unit is Kg.
• Mass of a body does not change from place to place.
• The weight of the body is the force with which it is attracted towards the centre of earth and it is given by w=mg.
• Weight of the body is a vector quantity and its unit is Newton
• The centre of gravity of a body is that point at which whole weight of the body appears to act.
• Weight of the body is a variable quantity and it changes from place to place.

Weight of a body in a lift:

• When lift is at rest or in uniform motion then apparent weight is equal to the real weight of the body, w=mg.
• When lift is accelerating upward then apparent weight is greater than the real weight of the body i.e. w=m(g+a)
• When lift is accelerating downward then apparent weight of the body is less than the real weight of the body i.e. w=m(g-a).
• When lift is falling freely under gravity the apparent weight of the body is zero i.e.

          W=m(g-g) as a =g
         w=0

• Weight of the body on moon is lesser than the weight of the body on earth as the acceleration due to gravity at the moon is less than the acceleration due to gravity on earth.  Acceleration due to gravity on Earth is 6 times than that of on the moon.

Planets:

• Planets are the heavenly bodies which  revolves around the sun in a specific orbit or path.
• Our solar system contains eight planets as Pluto losses its planet status.

Kepler’s Laws of Planetary Motion:

Kepler gives three laws which are as follows:

• All planets revolve around the sun in elliptical orbits with the sun at its one focus.
• The areal speed of planet around the sun is constant.
• The square of the time period of revolution of a planet around the sun is directly proportional to the cube of the semi-major axis of its elliptical orbit

Satellite:

• A heavenly body revolving around a planet in an orbit is called a satellite.
• Moon is the natural satellite of the earth.

There are two types of artificial satellites:

Geostationary Satellite:

• It revolves around the earth in equatorial orbits which is also called Geostationary or Geosynchronous orbit.
• They revolve around the earth at the height of  36000 Km
• There period of rotation is same as the earth’s time period of rotation around its own axis i.e. 24 hours.
• These satellites appear to be stationary.

Polar Satellite:

These satellites revolve around the earth in polar orbits at a height of around 800 km.
The time period of rotation of these satellite is 84 minutes.

Period of Revolution of a satellite:

• Time taken by a satellite to complete one revolution in its orbit is called its period of revolution.
• Period of revolution= Circumference of orbit/ orbital speed
• Period of revolution of a satellite depends upon the height of satellite from the surface of earth, greater its height from earth surface more will be its period of revolution.
•  Period of revolution is independent of its mass.

Escape Velocity:

• The minimum velocity with which when an object is thrown vertically upwards from the earth’s surface just crosses the earth’s gravitational field and never returns.
• Escape velocity=(2gr)^1/2
• Its value on earth surface is 11.2 km/sec
• When orbital speed is is increased by 41% i.e √2 times then it will escape from its orbit.

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Atomic and Nuclear Physics

Cathode Rays

Cathode rays, discovered by Sir William Crooke and its properties are

• travel in straight lines.
• Produce fluorescence.
• can penetrate through thin foils of metal and deflected by both electric and magnetic fields.
• have velocity ranging 1/30th to 1/10th of the velocity of light.

Positive or Canal Rays

• These rays were discovered by Goldstein.
• The positive ray consists of positively charged particles.
• These rays travel in straight line.
• These rays are deflected by electric and magnetic fields.
• These rays can produce ionization in gases.

X-Rays

• X-rays are electromagnetic waves with wavelength range 0.1 A-100 A.
• X-rays were discovered by Roentgen.
• X-rays travels in straight line.
• Long exposures of X – rays in injurious for human body.
• X – rays shows photoelectric effect.

Uses of X-Rays

• In medical sciences X-rays are used in surgery for the detection of fracture, diseased organs, foreign matter like bullet, stones etc. They are used in treatment of cancer and in skin diseases.
• In Engineering, X-rays are used in detecting faults, cracks, flaws and gas pockets in the finished metal products and in heavy metal sheets.
• In Scientific Work, X-rays are used in studying crystal structure and complex molecules.
• In Custom Department X-rays are used in custom department for detection of banned materials kept hidden.

Radioactivity

• Radioactivity was discovered by Henry Becquerel, Madame Curie and Pierre Curie for which they jointly won Nobel Prize.

Nuclear Fission

• Atom Bomb is based on nuclear fission. U²³⁵ and Pu²³⁹ are used as fissionable material.
• Nuclear fission was first demonstrated by Halin and Fritz Strassmann.

Nuclear Fusion

• When two or more light nuclei combined together to form a heavier nucleus is called as nuclear fusion.
• For the nuclear fusion, a temperature of the order of 10⁸ K is required.
• Hydrogen Bomb was made by the American Scientist in 1952. This is based on nuclear fusion. It is 1000 times more powerful than atom bomb.

Nuclear Reactor or Atomic Pile

• Nuclear reactor is an arrangement, in which controlled nuclear fission reaction takes place.
• First nuclear reactor was established in Chicago University under the supervision of Prof Enrico Fermi.
• Heavy water, graphite and beryllium oxide are used to slow down the fast moving neutrons. They are called moderate.

Uses of Nuclear Reactor
(i)To produce electrical energy from the energy released during fission.
(ii)To produce different isotopes, this can be used medical, physical and agriculture science.
There are several components of nuclear reactor which are as follows:

• Fissionable Fuel U²³⁵ or U²³⁹ is used.
• Moderator decreases the energy of neutrons, so that they can be further used for fission reaction.
• Heavy water and graphite are used as moderator.
• Control Rod rods of cadmium or boron are used to absorb the excess neutrons produced in fission of uranium nucleus, so that the chain reaction.

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Electricity

Electricity:

• Electricity deals with the motion of the electric charge.
• Electric charge is a scalar quantity is a scalar quantity its quantity is Coulomb.
• Electricity produced by the friction between two bodies is called static electricity or frictional electricity e.g. generation of electric charge on rubbing the plastic comb with dry hair.
• One body get positive charge and other body get negatively charged.

Coulomb Law:

The magnitude of the electrostatic force of interaction between two charge points is directly proportional to the scalar multiplication of the magnitudes of charges and inversely proportional to the square of the distance between them.

Electric Field:

• The space in the surrounding of any charge in which its influence can be experienced by other charge is called electric field.
• Electric field intensity (E) at any point is defined as the electrostatic force acting per unit positive test charge at that point. Its unit is newton/coulomb.
• E=F/q
• Electric field intensity is inversely proportional to the square of the distance r from the point charge.

Electric Field Lines:

• Electric field line is an imaginary lines or curve drawn through a region of space so that its tangent at any point is in the direction of the electric field vector at that point.
• Two lines an never intersect, electric field always start from positive end and always ends on negative charge and do not start or stop in the mid.

Electric potential:

• Electric potential at any point in an electric field is equal to the work done per unit charge in carrying at least a test charge from infinity to that point. Its unit is joule/coulomb.
• Potential difference between two points in electric field is equal to the work done per unit charge in carrying a positive test charge from one point to the other point.
• Potential difference decides the flow of charge between two points in electric field.
• Positive charge always tends to move from higher potential towards lower potential.
• Inside closed metallic body electric field inside it is zero.

Electric current:

• Electric current is the flow of charge in respect to time.
• Electric current=q/t
• An electric current whose direction does not change with time is called direct current (D.C).
• An electric current whose direction changes with time is called alternating current (A.C).
• In solids current flow due to flow of electrons and in liquid current flow due to flow of ions as well as electrons and  in semiconductors due to flow of electrons and holes.

Resistance:

• The resistance offered by any material in the flow of current is called as electrical resistance. Its S.I unit is ohm and [ML²T^-3A^-2] is its dimension.
• R=PL/A
• L=length of conductor
• A=cross sectional area
• P= resistivity of the material.
• Conductance
• Conductance or conductivity is the reciprocal of resistance and the resistivity of the material respectively. Its SI unit is mho.

Resistivity

• The resistivity of a material is equal to the electrical resistance of its wire of unit length and of unit area of cross section. It unit is ohm-meter.
• Resistivity of a material depends on the temperature and nature of material. It is independent of dimensions of the conductor, i.e. length, area of cross-section.
• Resistivity of metals increases with increase in temperature.
• Resistivity is low for metals, more for semiconductors and very high for alloys.

Combination of Resistances

• Resistance can be connected in two ways i.e. in parallel and in series.
• If resistance R_1, R₂ and R₃ are connected in series their equivalent resistance is given by

R= R₁+R₂+R₃

• In series combination equal current flows through each resistors.
• If resistance R_1, R2 and R3 are connected in parallel then equivalent resistance is given by.

1/R =1/R₁ +1/R₂ +1/R₃

Ohm’s Law

• It states that if physical conditions of any conductor such as temperature, pressure etc. are remain unchanged then electric current(I) through  it is directly proportional to the potential difference(V) applied across its ends.
•  V=IR

Kirchoff’s Law:

Kirchoff current law: states that  the net current on a junction in an electrical circuit will be zero. It is based on conservation of charge.
Kirchoff’s Voltage Law:  states that the algebraic sum of all potential difference along a closed loop is Zero. It is based on conservation of energy.

Electric Cell:

• An electric cell is a device which converts chemical energy into electrical energy.
• Electric cell are of two types:
• Primary cell: cannot be charged. Voltaic, Daniell and Leclanche cells are primary cells.
• Secondary Cell: can be charged again & again. Acid and alkali accumulators are secondary cells.

Joule’s Law of Heating

• Joule heating describes the process where the energy of an electric current is converted into heat as it flows through a wire due to the resistance of wire. Heat produced in the conductor due to electric current in time “t” is given by
• H=VIT=I²RT=V²t/r
• Electric bulb and heater works on the basis of heating effect produced by the current.

Chemical Effect of Electric current:

• When an electric current is passed through an acidic or basic solution, it decomposes into  its positive and negative ions. The positive ions collect at the negative electrode(Cathode) and the  negative ion is collected at the  positive electrode(anode).This phenomenon is called electrolysis.

Faraday’s Law of Electrolysis

First law:

• The total mass (M) deposited at an electrode in the process of electrolysis is directly proportional to the total charge (q) passed through the electrolyte.
• M=Zq, where Z is  electrochemical equivalent of the substance deposited at electrode.

Second law:

• If same strength of electric current is allowed to passed through different electrolytes for the same time, then mass deposited at the electrodes is directly proportional to their chemical equivalent.
• M₁/M₂ =E₁/E₂

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Magnetism

• In magnetism we study about the magnet and its properties

Magnet

• A magnet is a material which can attract iron objects.
• A natural magnet is an ore of iron (Fe₃O₄) called magnetite or lodestone.
• A magnet which is prepared artificially, is called an artificial magnet.

For Example

• A bar magnet, a horse-shoe magnet etc.
• A freely suspended magnet always aligns itself into North-South direction. Like magnetic poles repel and unlike magnetic poles attract each other.
• A current-carrying coil containing a soft iron core, is called an electromagnet.
• An electromagnet is utilised in electric bell, telegraph receiver, telephone diaphragm, transformer, dynamo etc.
• Permanent magnets are made of steel and temporary magnet or electromagnets are made of soft iron because steel cannot magnetised easily but when it is magnetised one time, cannot be demagnetised easily. The soft iron can be magnetised or demagnetised easily.

Properties of Magnet

• Attractive property A magnet can attract small pieces of magnetic substances like iron, steel, cobalt, nickel etc. The attraction is maximum at poles. Unlike poles attract and like poles repel.
• Directive property A magnet, when suspended freely, aligns itself approximately along geographical N-S line.
• Magnetic poles exist in pairs If a magnet is cut into two equal parts transverse to its length, then N and S-poles of the magnet do not get separated.

Magnetic Field

• The space in the surrounding of a magnet or a current carrying conductor in which its magnetic effect can be experienced, is called magnetic field.
• Magnetic lines of force is an imaginary line drawn in magnetic field at which a magnetic North pole will move, if it is free to do so.
• A tangent drawn at any point of a magnetic line of force represents the direction of magnetic field at that point.
• The magnetic flux linked with a surface is equal to the total number of magnetic lines of force passing through that surface normally. Its unit is weber.
• Magnetic flux, f = A. = BA cos q
• Magnetic Force Acting on a Charge
• Moving in Uniform Magnetic Field

The magnetic force on a moving charge in a magnetic field is given by F = Bqv sin q
where, B = magnetic field, q = charge, v = speed
q = angle between the direction of motion and magnetic field.
Magnetic Force Acting on a Current-Carrying Conductor Placed in Uniform Magnetic Field

• If a conductor carrying element / is placed in a magnetic field, the magnetic force on it is given by  F = Bill sin q

where, l = electric current flowing through the conductor  q = angle between the direction of current and magnetic field.
The direction of this force can be find out by Fleming's left hand rule which is given below.

• If we stretch the thumb, then the force finger and the middle finger of left hand in such a way that all three are perpendicular to each other and if fore finger represents the direction of magnetic field, middle finger represents the direction of current flowing through the conductor, then thumb will represent the direction of magnetic force.

Earth's Magnetism

• The earth has its own magnetic field and it resembles that of a magnetic dipole located at the centre of the earth. The pole near the geographic North of the earth is called the magnetic North pole. Similarly, the pole near the geographic South pole is called the magnetic South pole.
• The Earth's magnetic field diverts charged particle coming from space towards its poles and saves living beings from being severely harmed.
• Magnetic compass A magnetic needle which always direct in North-South (N-S) direction.
• Neutral point A point in a magnetic region where the net magnetic field is zero.

Magnetic Storm
Local disturbances in the earth's magnetic field which can damage telecommunication which are probably caused by lump of charged particles emanating from the sun is known as magnetic storm.
Coil Places in Uniform Magnetic Field
When a coil having number of turns N, each of area of cross-section A carrying current l is placed in a uniform magnetic field B, then a torque acts on it, which tries to rotate it.
Torque,  τ= NB/A sin q
Moving Coil Galvanometer

• A moving coil galvanometer is used to detect the presence of current and the direction of current in any circuit.
• When current is passed through a coil, suspended in a magnetic field, a torque acts on it. As coil rotates, a restoring torque acts on phospher bronze strip due to twist produce in it. In equilibrium, both torques become equal the pointer stops for a short moment and coil starts to rotate in opposite direction.

Ammeter and Voltmeter

• An ammeter is an instrument used to measure electric current. It is always connected in series. The resistance of an ideal ammeter is zero.
• A galvanometer can be converted into an ammeter by connecting a low resistance in parallel.
• A voltmeter is a device used to measure potential difference between two points in an electric circuit.
• The resistance of an ideal voltmeter is infinity. It is always connected in parallel.
• A galvanometer can be converted into a voltmeter by connecting a high resistance in series.
• A small resistance connected in parallel with the load resistance to reduce amount of electric current through resistor is called shunt.

Magnetic Substances

• There are three types of magnetic substances Paramagnetic, Diamagnetic and Ferromagnetic.

Paramagnetic Substances

• Those substances which are feebly magnetised in the direction of magnetic field when placed in strong magnetic field, are called paramagnetic substances. For example,- Aluminium, platinum, chromium, manganese, solutions of salts of iron, nickel, oxygen etc.

• These substances are attracted towards strong magnetic field in a non-uniform magnetic field.
• The magnetism of these substances decrease with increase in temperature.

Diamagnetic Substances

• Those substances which are feebly magnetised in the opposite direction of magnetic field when placed in strong magnetic field, are called diamagnetic substances. For example: Gold, Silver, zinc, copper, mercury, water, alcohol, air, hydrogen etc.

• These substances are attracted towards weak magnetic field in a non-uniform magnetic field.
• The magnetism produced in these substances does not change with increase or decrease in temperature.

Ferromagnetic Substances

• Those substances which are strongly magnetised in the direction of magnetic field when placed in it, are called ferromagnetic substances. For example –iron, nickel, cobalt, etc.
• The magnetism produced in these substances decreases with increase in temperature and at a particular temperature, called Curie temperature.
• At the Curie temperature, a paramagnetic substance becomes diamagnetic.
• The Curie law is Xm ∝1/T (where,   Xm= magnetic susceptibility of a paramagnetic substance and T = temperature)

• Curie temperature for iron is 770⁰C and for nickel is 358⁰

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Heat and Thermodynamics

Heat

• Heat is a form of energy, which measures the sensation or perception of warmness or coldness of a body or environment
• Its unit are calorie, kilocalorie or joule.
• 1 calorie = 4.18 joule.

Temperature

• Temperature is the measurement of hotness or coldness of a body.
• When two bodies are placed in contact, het always flows from a body at higher temperature to the body at lower temperature.
• An instrument used to measure the temperature of a body is called a thermometer.
• The normal temperature of a human body is 37⁰C or 98.4^{0 F}
• - 40⁰ is the temperature at which Celsius and Fahrenheit thermometers read same.
• The clinical thermometer reads from 96⁰F to 110⁰
• White roof keeps the house cooler in summer than black roof because white roof reflects more and absorbs less heat rays whereas black roof absorbs more and reflects less heat rays.
• Ice wrapped in a blanket does not melt away quick because woolen blanket is a bad conductor of heat.
• Silver is the best conductor of heat.
• Cooking utensils are made of aluminum, brass and steel because these substances have low specific heat and high conductivity.

Thermal Expansion

• Thermal expansion is the increase in size on heating.
• A solid can undergo three types of expansions

(i) Linear expansion
(ii) Superficial expansion
(iii) Cubical expansion

• Telephone wires are kept loose to allow the wires for contraction in winter.
• A gap is provided between two iron tracks of the railway track, so that rails can  easily expand during summer  and do not bend.

Specific Heat

• The amount of heat required to raise the temperature of unit mass of a substance through 1⁰C, is called its specific heat.
• When temperature of water is increased from 0⁰C, then its volume decreases upto 4⁰C, becomes minimum at 4⁰C and then increases.
• This behaviour of water around 4⁰C is called anomalous expansion of water.

Latent Heat

• The heat energy absorbed or released at constant temperature per unit mass for change of state is called the latent heat.
• Latent heat of fusion of ice is 80 cal/g.
• Latent heat of vaporization of steam is 536 cal/g.
• Hot water burns are less severe than that of steam burns because steam has high latent heat.

Evaporation

• It is the slow process of a conversion of liquid into its vapour even below its boiling temperature.
• The amount of water vapour in air is called humidity.
• Relative humidity is measured by hygrometer.
• Relative humidity increase with the increase of temperature.

Transmission of Heat

• Transfer of heat from one place to other place is called transmission of heat.
• In solids, transmission of heat takes place by conduction process.
• In liquids and gases, transmission of heat takes place by convection process. In room, ventilators are provided to escape the hot air by convection.
• Heat from the Sun reaches the Earth by radiation.

Simple Pendulum

• Simple pendulum is a heavy point mass suspended from a rigid support by means of an elastic and inextensible string.
• The maximum time period of a simple pendulum is 84.6 min.
• The time period of a simple pendulum does not depend upon the mass, shape and size of the bob and its amplitude of oscillation. A pendulum clock goes slow in summer and fast in winter.
• If a simple pendulum is suspended in a lift descending down with acceleration, then time period of pendulum will increase. If lift is ascending, then time period of pendulum will decrease.
• If a lift falling freely under gravity, then the time period of the pendulum is infinite.

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Types and Properties of Waves

WAVE

• A wave is a disturbance, which propagates energy from one place to the other without the transportation of matter.

Waves are broadly of two types:

• Mechanical wave (longitudinal wave and transverse wave)
• Electromagnetic wave

Longitudinal Waves

• In this wave the particles of the medium vibrate in the direction of propagation of wave.
• Waves on springs or sound waves in air are examples of longitudinal waves.

Transverse Waves

• In this wave the particles of the medium vibrate perpendicular to the direction of propagation of wave.
• Waves on strings under tension, waves on the surface of water are the examples of transverse waves.

Electromagnetic Waves

• The waves, which do not require medium for their propagation i.e., which can propagate even through the vacuum are called electromagnetic waves.
• Light radio waves, X-rays etc are the examples of electromagnetic wave. These waves propagate with the velocity of light in vacuum.

Sound Waves
Sound waves are longitudinal mechanical waves. Eased on their frequency range sound waves are divided into following categories.

• The sound waves which lie in the frequency range 20 Hz to 20000 Hz are called audible waves.
• The sound waves having frequencies less than 20 Hz are called infrasonic
• The sound waves having frequencies greater than 20000 Hz are called ultrasonic waves.
• Ultrasonic waves are used for sending signals, measuring the depth of see, cleaning clothes and machinery parts, remaining lamp short from chimney of factories and in ultrasonography.

Speed of Sound

• Speed of sound is maximum in solids minimum in gases.
• When sound goes from one medium to another medium, its speed and wave length changes, but frequency remain unchanged. The speed of sound remains unchanged by the increase or decrease of pressure.
• The speed of sound increases with the increase of temperature of the medium.
• The speed of sound is more in humid air than in dry air because the density of humid air is less than the density.

Echo:  The repetition of sound due to reflection of sound waves is called an echo.
Intensity:  It is defined as amount of energy passing normally per unit area held around that point per source unit time.
Pitch: The sensation of a frequency is commonly referred to as the pitch of a sound.
Sonar:  It stands for sound navigation and ranging. It is used to measure the depth of a sea, to locate the enemy submarines and shipwrecks.
Doppler's Effect
If there is a relative motion between source of sound and observer, the apparent frequency of sound heard by the observer is different from the actual frequency of sound emitted by the source. 1 his phenomenon is called Doppler's Effect.

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  Scientific Instrument and its Uses

• Rain Gauge: An apparatus for recording rainfall at a particular place.
• Radiometer: It measures the emission of radiant energy.
• Refractometer: It measures· refractive index.
• Cyclotron: A charged particle accelerator which can accelerate charged particles to high energies.
• Dynamo: It converts mechanical energy into electrical energy.
• Dynamometer: It measures electric power
• Electrometer: It measure electricity
• Hygrometer: It measures humidity in air.
• Hydrophone: It measures sound under water.
• Electroscope: It detects presence of an electric charge.
• Galvanometer: It measures the electric current of low magnitude.
• Hydrometer: It measures the specific gravity of liquids.
• Potentiometer: It is used for comparing electromotive force of cells.
• Pyrometer: It measures very high temperature.
• Cinematography: It is an instrument used in cinema making to throw on screen and enlarged image of photograph.
• Crescograph: It measures the growth in plants.
• Kymograph: It graphically records physiological movements (Blood pressure and heart beat).
• Lactometer: It determines the purity of milk.
• Manometer: It measures the pressure of gases.
• Mariner’s compass: It is an instrument used by the sailors to determine the direction.
• Microphone: It converts the sound waves into electrical vibrations and to magnify the sound.
• Microscope: It is used to obtain magnified view of small objects.
• Odometer: An instrument by which the distance covered by wheeled vehicles is measured.
• Phonograph: An instrument for producing sound.
• Radar: It is used for detecting the direction and range of an approaching plane by means of radio microwaves.

• Saccharimeter: It measures the amount of sugar in the solution.
• Photometer: The instrument compares the luminous intensity of the source of light
• Periscope: It is used to view objects above sea level (used in sub-marines).
• Endoscope: It examines internal parts of the body.
• Eudiometer: A glass tube for measuring volume changes in chemical reactions between gases.
• Fathometer: It measures the depth of the ocean.

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Uses of Metals

 

Metals:

• Metals are good conductors of heat & electricity and are malleable and ductile.
• Gold and silver are most malleable and best ductile metals.
• Silver is the best conductor of heat followed by copper.
• Aluminium and copper are good conductors of heat that’s why cooking utensils are made of them.
• Mercury offers high resistance to the flow of electric current.
• Sodium and potassium are so soft that they can be easily cut with knife.
• Metals are electropositive in nature.
• Almost all the metal oxide are  basic in nature but zinc oxide and aluminium oxide are amphoteric.

Alkali metals and their compounds

• Metals of first group are alkali metals.
•  This group lies in the s-block of the periodic table of elements as all alkali metals have their outermost electron in an s-orbital.
• Lithium, sodium, potassium, rubidium and cesium are alkali metals.
• These metals are stored under kerosene  or liquid paraffin’s to protect them from action of air.

 Sodium chloride (NaCl):  

• Commonly known as table salt
• Used in the manufacturing of sodium hydroxide and chlorine gas.
• It is used as a starting material in the manufacturing of caustic soda.
• It is used in the removing of ice from  road, now a- days CaCl₂ and MgCl₂ are also used for this purpose.

Sodium hydroxide (NaOH):

• Used in the refining of bauxite material.
• Used in soap, dyes and artificial industries.

Sodium bicarbonate (NaHCO₃):

• It is commonly known as baking soda.
• Used for wool washing.
• Used in the fire extinguisher.

Sodium carbonate (Na₂CO₃)

1. It is commonly known as washing soda.
2. Used for softening of hard water.
3. Mixture of sodium carbonate and potassium carbonate is known as Fusion mixture.

Sodium Sulphate:

• It is commonly known as Glauber’s salt.
• It is used as purgative.

Sodium thiosulphate:

• It is commonly known as Hypo and used in the photography as fixing agent.

Potassium carbonate:

• It is known as pearl ash.

Potassium hydroxide:

• Commonly known as caustic potash.
• Use in the preparation of soft soap.
• Its aqueous solution is known as potash Iye.

Potassium superoxide.

• Used in space capsules, submarines and breathing mask as it removes in carbon dioxide and carbon monoixide.

Alkaline Earth Metals and their compounds

The alkaline earth metals are six elements in column (group) 2 of the Periodic table.
They are beryllium (Be),magnesium(Mg),calcium (Ca), strontium (Sr),barium (Ba), and radium (Ra).They have very similar properties: they are all shiny, silvery-white, somewhat reactive metal at same temperature and pressure.

• Mg(OH₂) is known as milk of magnesia and use as an antacid.

Calcium oxide

• It is also known as quick lime.
• Used in the manufacturing of calcium chloride, cement and bleaching powder.

Calcium sulphate (CaSO4):

The compound exists in three levels of hydration:

• anhydrous state (mineral name: "anhydrite") with the formula CaSO₄
• dihydrate (mineral name: "gypsum") with the formula CaSO₄(H₂O)₂.
• hemihydrate with the formula CaSO₄(H₂O)_0.5
• It loses a part of water to form plaster of Paris.
• Plaster of Paris is a white powder which becomes hard on contact with water and is used in the manufacturing of statues.

Some Important Metals & Their Uses

Aluminium (Al):

• Ore of aluminium is bauxite.
• It is the third most abundant element in the earth’s crust.
• Used in the manufacturing of cooking utensils.
• Ammonal , a mixture of aluminium powder and ammonium nitrate is used as an explosive.

Tin:

• The ore of tin is Cassiterite.
• The process of converting white tin to grey tin is known as tin disease or tin plague.
• Used in plating of iron to protect the iron from rusting.
• Tin amalgam is used in the manufacturing of mirrors.

Lead(Pb)

• Main ore of lead is galena.
• Use in the preparation of sulphuric acid through chamber process.
• Lead acetate is known as sugar of lead.

Zinc(Zn):

• It is used in the galvanisation process to prevent the rusting of iron.
• Zinc sulphide is used in the preparation of X-ray screens.
• Zinc oxide is known as philosopher wool.

Mercury(Hg):

• It is the only metal which is liquid at room temperature.
• It forms alloys with all other metal except iron and platinum.

Nickel(Ni):

• Silvery white soft metal.
• Used as anode in Edison batteries.

Iron(Fe)

• Extracted from the haematite ore and do not occur in Free State due to its reactivity.
• Ferric chloride is used as stypic to stop bleeding from the cut.
• Ferrous sulphate is used in making blue black ink.  
  

  Stainless Steel

• It is an alloy of iron, chromium and nickel.
• Used in making automobiles parts and utensils

Uses of Metals for competitive exams

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Basics of Probability

Probability

A word which can also be used in the place of ‘Probability’ is ‘Chance’. We all are well aware of the word ‘chance’. We use it in our daily life. Whatever we do, whatever we observe, there is always a chance that this is going to happen or not. When we want to find out the value of this chance in a quantitative form, at that point of time we use ‘Probability’ at the place of ‘Chance’.

Some basic terms related to probability:

Experiment: Whatever we do, is called experiment.
Outcome: Whatever is the result of the experiment is known as the outcome.
Favourable Outcome: The outcome in which we are interested is known as favorable outcome.
Total possible outcomes:  All possibilities related to the result of experiment.
If one is aware with all the basic terms of probability, then the probability of any event / experiment can be found out by dividing the favourable outcome by total possible outcomes.
For example: Suppose we have a pack of cards and we want to pick a king of red then there will be less chance that we will pick out the same one. But let us find this quantitatively.
In this example: Experiment – Picking out one card from a pack of 52 cards.
Favourable outcome – Card picked out is red king (King of Heart or Diamond) (Only 2)
Total possible outcomes – Card picked out is any one of the total 52 cards.

Probability = (Favourable outcome / Total possible outcomes)

Combination concept

Combination is also known as collection. Whenever we deal with probability questions, we use only Combination concept of ‘Permutation and Combination’. The reason is that in probability, we only have to collect or pick the things. We don’t arrange them after picking out. So once a student knows the basics of Combination can deal with probability questions in easy way.
The formula used for combination is ⁿC_r
ⁿC­_r = n! / [r! x (n-r)!]
ⁿC­_r = [n x (n-1) x (n-2) x…...x(n-r+1) x (n-r) X…....x 1] / [1x 2 x 3….. x r] x [(n-r) x……..3 x 2 x 1]
ⁿC­_r = [n x (n-1) x (n-2) x (n-3)….. x (n-r+1)] / [1x 2 x 3….. x r]
For example: ¹²C­₂  = 12!/ [2! X (12-2)!] = 12!/ (2! X 10!) = [12 x 11] / [1 x 2] = 66
⁵C₂ = [5 x 4] / [1 x 2] = 10
ⁿC_r = ⁿC_(n-r)
For example:  ⁵C₃ = [5 x 4 x 3] / [1 x 2 x 3] = [5 x 4]/[1 x 2] = ⁵C₂ = 10
  ¹⁰C₇ = ¹⁰C₃ = [10 x 9 x 8]/[1 x 2 x 3] = 120

Various types of probability questions

Let us see how we can solve the probability questions, by taking the example of previous years questions asked in banking exams.

• When probability of two or more events is given: In this case, We use multiplication when both the events are going to happen (i.e. when the relation between the events is defined or described using ‘and’). We use addition when only one of the events will happen (i.e. when the relation between the events is defined or described using ‘or’).

Two people A and B go for an interview, the probability of A clearing the interview is 1/2 and probability of B clearing the interview is 1/4.
Q-1) What is the probability that both A and B will clear the interview?
Solution: We will multiply the probability of happening of both the events.
(1/2) x (1/4) = 1/8
Q-2) What is the probability that either one of them will clear the interview?
Solution: We will add the probability of happening of both the events.
(1/2) + (1/4) = 3/4
Q-3) What is the probability that only A will clear the interview?
Solution: We will multiply the probability of happening of event A and non-happening of event B.
(1/2) x [1-(1/4)] = (1/2) x (3/4) = 3/8
Note: Probability of non-happening of an event is always found out by subtracting probability of happening of that event from 1. The reason is that an event may or may not take place. So probability of happening of the event and non-happening of the event always add up to 1.

Probability of non-happening of an event = 1 – (Happening of an event)

Q-4) What is the probability that only B will clear the interview?
Solution: We will multiply the probability of non-happening of event A and happening of event B.
[1-(1/2)] x (1/4) = (1/2) X (1/4) = 1/8

• When we have to choose or pick out things from a bag/group: In this case, we use the concept of combination because we are choosing (selecting) things.

A bag contains 6 red shirts, 6 green shirts and 8 blue shirts.
Q-5) Two shirts are drawn randomly. What is the probability that both are green?
Solution: Favourable outcome – 2 Green shirts (out of 6)
Total possible outcomes – 2 shirts (out of 20)
Probability = ⁶C₂/²⁰C₂ = [(6x5) / (1x2)]/ [(20x19)/(1X2)] = (6x5)/(20x19) = 3/38
Q-6) Three shirts are drawn randomly. What is the probability that two are blue and one is red?
Solution: Favourable outcome – 2 blue (out of total 8) and 1 red shirt (out of total 6)
Total possible outcomes – 3 (out of 20)
Probability = (⁸C₂ x ⁶C₁)/ ²⁰C₃ = (28x6)/1140 = 14 / 95
Because we have ‘AND’ in favourable outcome, so we used multiplication.
Q-7) Two shirts are drawn randomly. What is the probability that both are either red or blue?
Solution: Favourable outcome – 2 red (out of total 6) or 2 blue (out of total 8)
Total possible outcomes – 2 (out of 20)
Probability = (⁶C₂+⁸C₂)/ ²⁰C₂ = (15+28)/190 = 43/190
Because we have ‘OR’ in favourable outcome, so we used addition.
Q-8) Out of 5 girls and 3 boys, 4 children are to be randomly selected for a quiz contest. What is the probability that all the selected children are girls?
Solution: Favourable outcome – 4 (out of 5)
Total possible outcomes – 4 (out of 8)
Probability = ⁵C₄/⁸C₄ = ⁵C₁/⁸C₄ = 5/70 = 1/14

• When dice are thrown: Concept of combination is not needed in these questions. We normally check the favourable and total possible outcomes by basic idea of a dice. The total possible outcomes are decided on the basis of no of throws or no of dices used. If two throws are made (or two dices are thrown) then the total possible outcomes can be found out by 6 x 6 = 36 (because these are the total possible combinations which can be seen).

Q-9) A die is thrown twice. What is the probability of getting a sum 7 from both the throws?
Solution: Favourable outcome – 6 [(1,6),(2,5),(3,4),(4,3),(5,2),(6,1)]
Total possible outcomes – 6x6 = 36
Probability = 6/36 = 1/6
Q-10) A die is thrown thrice. What is the probability of getting a sum 5?
Solution: Favourable outcomes – 6[(1,1,3),(1,3,1),(3,1,1),(1,2,2),(2,1,2),(2,2,1)]
Total possible outcomes – 6x6x6 = 216
Probability = 6/216 = 1/36

• When cards are chosen from a pack of cards: Here we use the concept of combination because we are choosing (selecting) cards from a whole pack of cards. The total possible outcomes are 52 if only one pack of cards is used.

Q-11) Two cards are picked simultaneously from a pack of cards. What is the probability that both the cards will be queen?
Solution: Favourable outcomes – 2 (out of 4)
Total possible outcomes – 2 (out of 52)
Probability = ⁴C₂/⁵²C₂ = [(4x3)/(1x2)]/[(52x51)/(1x2)] = (4x3)/(52x51) = 1/221
Q-12) Two cards are picked out one by one from a pack of cards with replacement. What is the probability that both the cards will be queen?
Solution: First pick out –
Favourable outcomes – 1 (out of 4)
Total possible outcomes – 1 (out of 52)
Probability = ⁴C₁/⁵²C₁ = 4/52 = 1/13
Second pick out –
Favorable outcome – 1 (out of 4)
Total possible outcomes – 1 (out of 52)
Probability = ⁴C₁/⁵²C₁ = 4/52 =1/13
Because both events are happening, so final probability = (1/13) x (1/13) = 1/169
Q-13) Two cards are picked out one by one from a pack of cards without replacement. What is the probability that both the cards will be queen?
Solution: First pick out –
Favourable outcomes – 1 (out of 4)
Total possible outcomes – 1 (out of 52)
Probability = ⁴C₁/⁵²C₁ = 4/52 = 1/13
Second pick out –
Favourable outcome – 1 (out of 3)
Total possible outcomes – 1 (out of 51)
Probability = ³C₁/⁵¹C₁ = 3/51 = 1/17
Because both events are happening, so final probability = (1/13) x (1/17) = 1/221

• When team/group/committee is made with some constraints: In these questions, we have to find out the probability of different possibilities and we add those probabilities because only one combination of team/group/committee will be formed at a time.

A committee of 3 members is to be made out of 3 men and 2 women.
Q-14)What is the probability that the committee has at least one woman?
Solution: Favourable outcomes – [1(out of 2 women) and 2(out of 3 men)]
Or [2(out of 2 women) and 1(out of 3 men)]
Total possible outcomes – 3 (out of 5)
Probability = [(²C₁x³C₂) + (²C₂x³C₁)] / ⁵C₃ = [(2x3) + (1x3)] / 10 = (6+3)/10 = 9/10
Q-15) What is the probability that he committee has at most one woman?
Solution: Favourable outcomes – [0(out of 2 women) and 3(out of 3 men)]
Or [1(out of 2 women) and 2(out of 3 men)]
Total possible outcomes – 3 (out of 5)
Probability = [(²C₀x³C₃) + (²C₁x³C₂)] / ⁵C₃ = (1+6)/10 = 7/10
So, keep in mind these basic concepts before moving ahead with probability questions.

SSC

Posted By Unknown

 

Mixture and Alligation

Question 1: 

 In a mixture of 75 litres, the ratio of milk to water is 2 : 1. The amount of water to be further added to the mixture so as to make the ratio of the milk to water 1 : 2 will be
(1) 45 litres
(2)  60 litres
(3)  75 litres
(4)  80 litres

Solution: 

In 75 litres of the mixture.

Let x litres of water be added,

Short Trick:

3 units = 75 l because 75 l was in ratio 2 : 1 initially.

Question 2:  

A mixture of 40 litres of milk and water contains 10% water. How much water must be added to make 20% water in the new mixture?
(1)  3 litres
(2)  4 litres
(3)  5 litres
(4)  6 litres

Solution 

(8 x 5 = 40 l which is the initial quantity. Hence 1 is also multiplied by 5)

Short Trick:

(40 + x) x 20% = 4 + x
x = 5l

Question 3:  

In three vessels each of 10 l capacity, mixture of milk and water is filled, the ratios of milk and water are 2 : 1, 3 : 1 and 3 : 2 in the three respective vessels, if all the three vessels are emptied into a single large vessel, find the proportion of milk and water in the mixture.
(1)  121 : 59
(2)  123 : 59
(3)  125 : 59
(4)  127 : 59

Solution:

2^nd Method :

L.C.M. of 3, 4 & 5. Hence 3 is multiplied by 4 x 5; 4 is multiplied by 3 x 5; 5 is multiplied by 3 x 4.

Question 4 :

  Vessels A and B contain mixtures of milk and water in the ratios 4 : 5 and 5 : 1 respectively. In what ratio should quantities of mixture be taken from A and B to form a mixture in which milk and water is in the ratio 5 : 4?
(1)  2 : 5
(2)  4 : 3
(3)  5 : 2
(4)  2 : 3

Solution: 

Quantity of milk in vessel A

Quantity of milk in vessel B

Quantity of milk in final mixture


So, mixture of vessels A and B are mixed in ratio of 5 : 2.

2^nd Method :

Question 5: 

50 g of an alloy of gold and silver contains 80% gold (by weight). The quantity of gold, that is to be mixed up with this alloy, so that it may contain 95% gold, is
(1)  200 g
(2)  150 g
(3)  50 g
(4)  10 g

Solution: 

Quantity of gold in the alloy

Let x gm of gold is added, then

Other Method: 

1 unit when multiplied by 50 gives 50g. Hence 3 unit is also multiplied by 50.

Tricks to solve Mixture and Alligation for competitive exam

Posted By Unknown