Gravitation Mock Test – Class 11 Physics

1. A planet is described as moving in an elliptical orbit around the Sun. The statement that best matches Kepler’s first law is

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

3. The graph of gravitational field magnitude against distance from an isolated point mass should be described as

4. A gravitational field around a body means a region where another mass

5. A graph is drawn between gravitational force and separation for two fixed point masses. The curve should show that

6. The dimension of gravitational potential is

7. The binding energy of a satellite in a circular orbit of radius is

8. For a geostationary satellite, use , , and . The orbital radius is closest to

9. At a height above Earth, the value of is . The ratio is

10. Use the orbit description below. An ellipse has two foci, and , and its geometric centre is . A planet moves on the ellipse around the Sun. According to Kepler’s first law, the Sun should be placed at

11. A proposed formula for escape speed is . It is rejected because has the dimension of

12. The expression can represent the binding energy of a circular satellite orbit. Its SI unit is

13. A circular satellite has total energy , where . Its kinetic energy, potential energy, and binding energy are respectively

14. A solution claims that a satellite needs twice the orbital speed of a satellite in the same circular orbit. The correct diagnosis is that the solution

15. At a point in space, the net gravitational field due to two masses is zero, but the gravitational potential there is not zero. This situation is possible because

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

17. In a Cavendish-type experiment, the main purpose is to measure

18. Newton’s universal law of gravitation states that the force between two point masses is

19. The time period of a satellite in a circular orbit of radius is obtained from

20. At the centre of Earth, the value of in the uniform-density model is

21. A planet moving around the Sun has a continuously changing velocity direction. This change most directly implies that the planet has

22. 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

23. A uniform spherical planet has radius and surface gravity . On a graph of interior gravitational field magnitude against distance from the centre, for , the slope is

24. A planet has radius , mass , and surface gravity . A satellite orbits at height above the surface. Its orbital period in terms of the near-surface orbital period is

25. The point-mass formula becomes unsafe at for a real planet because

26. Starting from Earth’s surface, the escape-speed derivation uses

27. A source mass creates gravitational potential . If the distance from is doubled, the potential becomes

28. Two small spheres of masses and are separated by . Taking , the gravitational force between them is closest to

29. For a body projected from distance from the centre of a planet of mass , the escape speed is

30. A common error in geostationary-orbit calculations is to substitute the height directly for in . The correction is that should be

31. Consider the statements about gravitational force.
I. It is always attractive.
II. It requires direct surface contact between two bodies.
III. For two bodies, it acts along the line joining their centres.
The suitable choice is

32. A body is moved slowly from Earth’s surface to a distance from Earth’s centre. If and , the work done by an external agent is closest to

33. A planet has density and radius . Its surface gravity is proportional to

34. The gravitational potential energy of masses and , separated by distance , is

35. The slope of the graph inside a uniform Earth, when , is

36. A student claims, “A geostationary satellite stays fixed because Earth’s gravity is zero at that height.” The best evaluation is that the claim is

37. A satellite has a circular equatorial orbit and moves eastward like Earth’s rotation, but its period is . It is

38. The table gives four arrangements of source masses around a test mass . Each source mass is at the same distance from .

The cases with zero net gravitational force on are

39. For a uniform spherical Earth, the gravitational potential is continuous at the surface. This means that

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

41. The SI unit of gravitational potential is

42. A planet has the same surface gravity as Earth but times Earth’s radius. Its mass and escape speed compared with Earth are

43. Gravitational potential at a point is defined as

44. The orbital speed of a satellite in a circular orbit of radius around a planet of mass is

45. A satellite in a circular orbit around Earth remains in orbit because Earth’s gravitational force provides

46. The statement that best contrasts altitude and depth variation of is

47. A graph is drawn with circular orbital speed on the vertical axis and orbital radius on the horizontal axis for satellites around the same planet. The graph should show that

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

49. Two masses and are placed at points and . A test mass is placed on the -axis outside the interval on the left side of . The net gravitational field there can be zero

50. Taking and , the time period of a satellite just above Earth’s surface is closest to