Gravitation Mock Test – Class 11 Physics

1. A graph of for a uniform spherical Earth is drawn from the centre to far outside Earth. The graph should

2. A planet’s density is doubled while its radius is also doubled. Its surface gravity, near-surface orbital speed, and escape speed become respectively

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

4. The orbital radius of a geostationary satellite is about from Earth’s centre. If Earth’s radius is , its height above Earth’s surface is closest to

5. A projectile is launched from Earth’s surface with speed and just reaches a maximum height above the surface. The required launch speed is

6. A satellite around a planet has . Taking , the planet’s mass is closest to

7. The following table lists possible satellite descriptions.

The geostationary case is

8. A passage says: “A spacecraft at radius has . Therefore it can escape because gravity exactly provides centripetal force.” The missing condition is that escape from the same radius requires

9. An object is moved from the equator to the pole. Ignoring local geological variations, its mass and weight change as

10. A mass of experiences a gravitational force of at a point. The gravitational field intensity at that point is

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

12. Kepler’s second law states that the line joining a planet and the Sun sweeps out

13. Gravitational potential energy of two masses is taken as zero when their separation is

14. In the limit , the gravitational potential tends to

15. A satellite’s circular orbit radius is increased. The correct combined change is that its orbital speed

16. A satellite orbits a planet of mean density just above its surface. Its time period depends on density as

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

18. 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

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

20. A relation is used for a spacecraft at very large . As , the relation predicts

21. In an orbiting satellite, the apparent weight of an object becomes zero when

22. A planet has mass and radius . If Earth’s surface gravity is , the planet’s surface gravity is

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

24. A mixed calculation gives for a satellite at some height above Earth. The corresponding centre-distance and height are

25. The equality of inertial mass and gravitational mass helps explain why, in vacuum near Earth,

26. Two satellites move in circular orbits of the same radius , one around planet of mass and one around planet of mass . The ratio is

27. A planet’s mass is made times larger while its radius is made times larger. Compared with the original planet, the surface gravity and escape speed become

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

29. Taking , , and , the estimated mass of Earth is closest to

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

The table is

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

32. A planet has radius , surface gravity , and a satellite moving just above its surface. The satellite’s time period is

33. In an elliptical orbit, the areal velocity of a planet about the Sun is constant. If the planet’s distance from the Sun becomes half and its angular speed is at the larger distance, the angular speed at the smaller distance is

34. A satellite in a stable circular orbit has negative total mechanical energy mainly because

35. Match each satellite type with its most suitable description.

36. In the uniform spherical Earth model, the gravitational field is maximum

37. Escape speed is independent of the mass of the escaping body because

38. 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.

39. Assertion: Work done by gravity in moving a body from one point to another is independent of the path followed. Reason: Gravitational force is conservative.

40. A body is at height above Earth’s surface. The gravitational potential at its position is

41. A circular satellite has period just above Earth’s surface. Another circular satellite around Earth has period . Its orbital radius and height above Earth’s surface are respectively

42. The graph of gravitational field for a uniform solid Earth is divided into two regions: Region P has , and Region Q has . The correct description is

43. Assertion: A geostationary satellite cannot be placed directly above a fixed point at Earth’s pole. Reason: A geostationary satellite must move in the equatorial plane.

44. A satellite in a circular orbit is sometimes described as “falling around Earth.” This phrase means that the satellite

45. A passage states: “A satellite is in circular orbit. Its engine is off. Its speed is steady, but its velocity is not constant.” The best reason is that

46. When the separation between two point masses is doubled while both masses remain unchanged, the gravitational force becomes

47. A graph of orbital speed against orbital radius for circular satellites is decreasing. If the horizontal axis is changed to , the relation between and becomes

48. For a satellite of mass moving in a circular orbit of radius around Earth of mass , the equation used to find orbital speed is

49. In a uniform-Earth model, the field at from Earth’s centre is

50. A uniform spherical planet has mass , radius , and surface gravity . At an interior point whose distance from the centre is , the potential difference between that point and the surface is