4. Stars appears to move from east to west because
5. Pa(Pascal) is the unit for
6. Planets do not twinkle because
7. Metals are good conductors of electricity because
8. Let a thin capillary tube be replaced with another tube of insufficient length then, we find water
9. Out of the following pairs, choose the pair in which the physical quantities do not have identical dimension?
10. If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same
11. Pick out the scalar quantity
12. Rectifiers are used to convert
13. out of the following, which is not emitted by radioactive substance?
14. Sound waves in air are
15. Magnetism at the centre of a bar magnet is
16. It is more difficult to walk on a sandy road than on a concrete road because
17. Find the maximum velocity for the overturn of a car moving on a circular track of radius 100 m. The co-efficient of friction between the road and tyre is 0.2
18. Of the following properties of a wave, the one that is independent of the other is its
19. Lux is the SI unit of
20. On a rainy day, small oil films on water show brilliant colours. This is due to
21. Point A is at a lower electrical potential than point B. An electron between them on the line joining them will
22. Materials for rain-proof coats and tents owe their water-proof properties to
23. RADAR is used for
24. Sound of frequency below 20 Hz is called
25. On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because