# G.K. Practice Test: Question Set - 12

1. Railway tracks are banked on curves
(A) Necessary centrifugal force may be obtained from the horizontal component weight of the train
(B) To avoid frictional force between the tracks and wheels
(C) Necessary centripetal force may be obtained from the horizontal component of the weight of the train
(D) The train may not fly off in the opposite direction

2. Light from the star, Alpha Centauri, which is nearest to the earth after the sun, reaches the earth in
(A) 4.2 seconds
(B) 42 seconds
(C) 4.2 years
(D) 42 years

3. ML2T-2 is the dimensional formula for
(A) Moment of inertia
(B) Pressure
(C) Elasticity
(D) Couple acting on a body

4. Large astronomical telescopes always use as objective
(A) Lens
(B) Mirror
(C) Combinations of lenses
(D) None of the above

5. It is easier to roll a barrel full of coal tar than to pull it because
(A) The full weight of the barrel comes into play when it is pulled
(B) The rolling friction is much less than the sliding friction
(C) More surface area of the barrel is in contact with the road when it is pulled
(D) Coal tar is a liquid and it flows in the barrel when it is rolled

6. Siphon will fail to work if
(A) The densities of the liquid in the two vessels are equal
(B) The level of the liquid in the two vessels is at the same height
(C) Both its limbs are of unequal length
(D) The temperature of the liquids in the two vessels is the same

7. Light from the Sun reaches us in nearly
(A) 2 minutes
(B) 4 minutes
(C) 8 minutes
(D) 16 minutes

8. On a rainy day, small oil films on water show brilliant colors. This is due to
(A) Dispersion
(B) Interference
(C) Diffraction
(D) Polarization

9. Inside an aeroplane, flying at a high altitude
(A) The pressure is the same as that outside
(B) Normal atmospheric pressure is maintained by the use of air pumps
(C) The pressure inside is less than the pressure outside
(D) Normal humidity and partial vacuum are maintained

10. Sound produced at a point is heard by a person after 5 second, while the same sound is heard by another person after 6 seconds. If the speed of sound is 300 m/s, what could be the maximum and minimum distances between the two persons?
(A) 1.8 km, 0.15 km
(B) 2.2 km, 0.20 km
(C) 2.8 km, 0.25 km
(D) 3.3 km, 0.30 km

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