Gravitation Mock Test – Class 11 Physics

1. The table compares horizontal launch speeds from the same high point above Earth, with air resistance neglected.

The table is

2. A body of mass is moved slowly from distance to distance from a planet’s centre. The work done by gravity is

3. At a distance from Earth’s centre, the escape speed is related to Earth’s surface escape speed by

4. Assertion: A mass placed at the centre of a square experiences zero net gravitational force if equal masses are placed at all four vertices. Reason: Forces due to opposite vertices are equal in magnitude and opposite in direction.

5. The orbital speed of a geostationary satellite of orbital radius may be written as

6. Assertion: A planet in an elliptical orbit moves faster when it is nearer the Sun. Reason: The line joining the planet and the Sun sweeps equal areas in equal time intervals.

7. A graph is drawn with on the horizontal axis and surface gravity on the vertical axis for planets having the same radius . The expected graph is

8. For a uniform solid sphere of radius , the gravitational field magnitude inside the sphere varies with distance from the centre as

9. A student applies to a mountain height above Earth’s surface. The mistake is that the formula is meant for

10. The following table compares two roles of mass.

The table is

11. A feather and a metal ball are dropped in a long vacuum tube near Earth. Their accelerations are equal mainly because

12. The Moon produces noticeable tides on Earth mainly because

13. Two planets move around the same star in nearly circular orbits. Planet has orbital radius , and planet has orbital radius . The ratio is

14. The gravitational potential at the surface of a planet is , where . The escape speed from the surface is

15. The table lists common errors and corrections.

The table is

16. A pair of masses is moved slowly from separation to separation . The work done by gravitational force during this motion is

17. Two ideas are compared for an orbiting satellite: “free fall” and “no gravity.” The correct comparison is that

18. Using , Earth’s escape speed can also be written as

19. Gravitation is best described as the interaction by which

20. A satellite in a circular orbit of radius has its speed increased to , where is the circular speed at that radius. Its speed at infinity, if it escapes, is

21. A person of mass stands on a weighing machine inside a lift falling freely with acceleration . The reading of the weighing machine is

22. A satellite in circular orbit is moved to a higher circular orbit. During this change, the final circular orbital speed is smaller, but external energy must be supplied. This is because the higher orbit has

23. A satellite is moving in a circular orbit. The gravitational force on it does no work over one complete revolution because

24. A graph is drawn for a fixed arrangement of several source masses. The horizontal axis is the test mass , and the vertical axis is the net gravitational force magnitude on it. If the source masses and distances are unchanged, the graph should be

25. A planet has radius and uniform density . The escape speed from its surface is proportional to

26. A thin uniform spherical shell has mass and radius . A small body is placed at a distance from the shell’s centre. The shell’s gravitational effect on the body is equivalent to

27. A planet has times Earth’s mass and times Earth’s radius. If Earth’s escape speed is , the planet’s escape speed is

28. A satellite is in a circular orbit of radius . Its kinetic energy is . If the satellite is shifted to a circular orbit of radius , its new kinetic energy is

29. A astronaut is in a satellite where the local gravitational field is . If the astronaut is freely orbiting with the satellite, the gravitational force and apparent weight are respectively

30. A satellite is in a circular orbit of radius . The engine supplies energy equal to half the satellite’s binding energy while the satellite is still at the same radius. Its total mechanical energy becomes

31. Two masses and are separated by . Taking , their gravitational potential energy is closest to

32. Four point masses are placed at the corners of a square of side . In cyclic order, the masses are , , , and . The gravitational potential at the centre of the square is

33. In a uniform solid Earth model, the gravitational potential is most negative at

34. The value of is very small. This explains why

35. A satellite is shifted from a circular orbit of radius to a circular orbit of radius around the same planet. Its total mechanical energy changes from to

36. The following table compares two causes of latitude variation in .

The table is

37. A satellite’s orbital radius is doubled. The ratio of its new orbital speed, escape speed from that radius, and period to their original values is

38. A planet has density and radius . Planet has density and radius . The ratio of their escape speeds is

39. The conservation idea most closely linked with Kepler’s second law is conservation of

40. A graph-like description says: the vertical axis represents area swept by the Sun-planet line, and the horizontal axis represents time. For one planet in its orbit, Kepler’s second law predicts a graph that is

41. For two spherical bodies separated by a gap, the distance in the gravitational force formula is measured

42. Assertion: The gravitational field inside a thin uniform spherical shell is zero everywhere. Reason: At an interior point, vector contributions from different parts of the shell cancel due to spherical symmetry.

43. At a height above Earth’s surface, the distance from Earth’s centre to a body is

44. A body is fired from Earth’s surface with speed , and at infinity its speed is , where is Earth’s escape speed. The launch speed is

45. A satellite moves in a circular orbit of radius with total energy . If its radius is decreased to , its new total energy is

46. A satellite formula uses , while a height description gives . For a satellite at height above Earth’s surface, the correct substitution in is

47. A point has two gravitational field contributions, east and north. The resultant field magnitude is

48. The SI unit of gravitational field intensity can be written as

49. A line graph of against for satellites around a planet has a smaller slope than the same type of graph for satellites around another planet. The first planet must have

50. Use the arrangement described below. The Moon is to the right of Earth. Point P is on Earth’s surface nearest the Moon, Point Q is at Earth’s centre, and Point R is on the far side. The Moon’s gravitational pull is strongest at