11. A liquid is kept in a regular cylindrical vessel up to a certain height . If this vessel is replaced by another cylindrical vessel having half the area of cross-section of the bottom, the pressure on the bottom will
- A. remain unaffected
- B. be reduced to half the earlier pressure
- C. be increase to twice the earlier pressure
- D. be reduced to one-fourth the earlier pressure
- Check Answer | Discussion
12. When a ball drops onto the floor it bounces. Why does it bounce?
- A. The floor is perfectly fluid
- B. The floor heats up on impact
- C. Newton's third law implies that for every action (drop), there is a reaction (bounce)
- D. The floor exerts a force on the ball during the impact
- Check Answer | Discussion
13. Gases begin to conduct electricity at the low pressure because
- A. at low pressure gases turn into plasma
- B. colliding electrones can acquire higher KE due to increased mean free path leading to ionisation of atoms
- C. atoms break up into electrons and protons and electron started conducting electricity
- D. the electrons in the atom move freely in low pressure
- Check Answer | Discussion
14. Telescopes are placed in space to view distant galaxies primarily to
- A. get closer to the observed objects
- B. avoid the absorption of light or other radiations in the atmosphere of the Earth
- C. avoid light pollution from the Earth's populated areas
- D. avoid steering the telescope against the Earth's motion
- Check Answer | Discussion
15. In scuba diving, while ascending towards the water surface, there is a danger of bursting the lungs. It is because
16. A solid sphere, disc and solid cylinder all of same mass and made of same material are allowed to roll down (from rest) on incline plane then
- A. disc will reach the bottom first
- B. solid sphere will reach the bottom first
- C. solid cylinder will reach the bottom first
- D. all of them will reach the bottom at the same time
- Check Answer | Discussion
17. A circular disc is to be made by using iron and aluminium so that it acquired maximum moment of inertia about the geometrical axis. It is possible with
- A. iron at interior and aluminium surrounding to it
- B. aluminium at interior and iron surrounding to it
- C. using iron and aluminium layers in alternate order
- D. None of the above
- Check Answer | Discussion
18. A current I flows through a potential difference V in an electrical circuit containing a resistance R. The product of V and I i.e., VI may be understood as
- A. resistance R
- B. heat generated by the circuit
- C. thermal power radiated by the circuit
- D. rate of change of resistance
- Check Answer | Discussion
19. Ohm's Law can also be taken as a statement for
- A. conservation of energy
- B. conservation of electric charge
- C. conservation of angular momentum
- D. non-conservation of momentum of the flowing charges
- Check Answer | Discussion
20. During sunrise and sunset, Sun appears reddist-orange bacause
- A. during that time, Sun emits only reddish-orange light
- B. all other colours are absorbed by the atmosphere
- C. reddish-orange light is least scattered by the atmosphere
- D. all other colours apart from reddish-orange are reflected back by the atmosphere
- Check Answer | Discussion
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