This is solution of CAPF science portion, You need not worry about difficult physics questions as they won’t be asked in civil services examination. Just focus on how to solve with limited knowldge

1. Which of the following statements is correct?
1. Gravitational waves were predicted by Albert Einstein in 1916 on the basis of his theory of General Relativity
2. Gravitational waves do also exist in the Newtonian theory of Gravitation
3. Gravitational Waves are to be detected by very sensitive detectors known as Interferometes
Select the correct answer using the code given below:
(a) 1only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3

• Very much in news
• CD newscards and explainers cover everything
• In any case, 2nd statement is false as quantum physics is not in Newtonian mechanics

2. Who among the following scientists of Indian origin is / has been the President of Royal Society?

(a) Ronald Ross
(b) Har Gobind Khorana
(c) Chandrasekhara Venkata Ramana
(d) Venkataraman Ramakrishnan

• Useless question
• Not doable

3. A change of state directly from solid to gas without changing into liquid state is called:

(a) Fusion
(b) Sublimation
(c) Diffusion
(d) Emulsion

• 5th standard science
• Eg. camphor

4. Water at 273 K is less effective in cooling than ice at the same temperature. It is because :

(a) water is difficult to handle
(b) water at 273 K has less energy than ice at the same temperature
(c) water at 273 K has more energy than ice at the same temperature
(d) water is not a cooling agent

• Common sense
• Cooling means energy should be transferred to coolant. Less energy means more energy could be transferred hence more coiling
• Easily the c
• In any case b and c are contradictory, one has to be true

5. Which one of the following is not a colloid?

(a) Milk
(b) Mud
(c) Butter
(d) Boric acid

• Even if you don’t know anything, you can easily spot odd one out
• Crystals form pure solution while colloids don’t
• Milk, mud, butter easily colloid

6. Which one of the following statements is not correct?

(a) Bleaching powder is prepared by the action of Chlorine on dry slaked lime [Ca(OH)2]
(b) Bleaching powder acts as a reducing agent in many chemical industries
(c) Bleaching powder is also known as chlorinated lime
(d) Bleaching powder is used for disinfecting drinking water

• Bleach – Ca(OH)2 . is oxidizing agent
• All fashion conscious people know this
• Even if you don’t know this, it can not act as reducing agent, it gives oxygen hence oxidizing

7. Which one of the following statements is not correct?
(a) Graphite is a non-metal
(b) Graphite is an allotrope of carbon
(c) Graphite is a conductor of electricity
(d) Graphite has a tetrahedral structure

• Graphite is carbon, allotrope, non metal, 1 and 2 easily true
• Conductor of electricity – reason for its widespread use
• It’s hexagonal – 6th std science
• So many questions have been asked on Graphite and graphene

8. Consider the following physical quantities: Energy , power, pressure, impulse, temperature, gravitational potential
Which of the above is / are the vector quantity / quantities ?
(a) Impulse only
(b) Impulse and pressure only
(c) Impulse , temperature and pressure
(d) Gravitational potential

• 9th std science
• Temperature can not be vector
• Vector is associated with a specific direction like velocity, force
• Pressure is in all directions not a vector
• Impulse is
• Though it’s given in class 11 NCERT, you don’t need to read that

9. A piece of stone tied to a string is made to revolve in a circular orbit of radius r with other end of the string as the centre. If the string breaks, the stone will:
(a) move away from the centre
(b) move towards the centre
(c) move along a tangent
(d) stop

• Newtonian laws of motion
• Inertia principle <will move in the initial direction>
• You would have observed this
• Again 9-10th std physics

10. Which one of the following statements is not true?

(a) The gravitational force of earth acting on a body of mass 1 kg is 9.8 newton
(b) The force acting on an object of mass 5 kg moving with a uniform velocity of 10 m/s on a frictionless surface is zero
(c) The SI unit of weight is kg
(d) The momentum of a man having mass 100 kg walking with a uniform velocity of 2 m/s is 200 newton second

• Kg is unit of mass
• Weight is force so unit would be newton

11. Which one of the following statements is correct?

(a) Acceleration due to gravity decreases with the increase of altitude
(b) Acceleration due to gravity increases with the increase of depth [assuming earth to be a sphere of uniform density]
(c) Acceleration due to gravity decreases with the increase of latitude
(d) Acceleration due to gravity is independent of the mass of the Earth

• Easy peasy 1st option
• You move away from a body, gravitational force would decrease
• Increase in altitude, away from earth. Don’t worry about other options
• But now learn them too

12. A Barometer kept in an elevator reads 760 mm when the elevator is at rest. When the elevator moves in the upward direction with increasing speed, the reading of the Barometer will be :
(a) 760 mm
(b) < 760 mm
(c) > 760 mm
(d) Zero

• Difficult question
• Don’t think too much
• You can apply your effective weight of m(g+a) to solve the problem

13. Which one of the following statements is not correct?

(a) The earth’s magnetic field is due to the motion of metals like iron and nickel in the core of the earth
(b) The magnetic field lines of force are widely separated near the poles of a magnet but these lines come closer to one another at other places
(c) If the cross sectional area of a magnetic field increases, but the flux remains the same, the flux density decreases
(d) When the speed of a conductor moving through a magnetic field is increases, the included voltage increases

• You would have seen the images
• Magnetic lines converge at the poles

14. Let a resistor having 4 ohm resistance be connected across the terminals of a 12 volt battery. Then the charge in coulomb passing through the resistor per second is :
(a) 12
(b) 4
(c) 3
(d) 0.33

• V = IR
• Current would be 3

15. Arrange the following substances in their order of increasing hardness:
1. Gypsum
2. Topaz
3. Fluorite
4. Feldspar
Select the correct answer using the code given below:
(a) 4-3-2-1
(b) 1-3-4-2
(c) 3-4-2-1
(d) 1-4-3-2

• NCERT physical geography
• Gysum would be the softest so you could easily eliminate 2 options

P.S. – Solutions of CSE pre 2013, 2014 ad 2015 with brief analysis will be at your desk by midnight

P.P.S. – Don’t be scared of science and technology