Gravitation Mock Test – Class 11 Physics

1. The Moon does not fall straight down to Earth mainly because it has

2. A relation check is made among three ideas: gravitational field, gravitational potential, and gravitational force on a test mass. The correct relation set is

3. Two satellites of equal mass orbit the same planet in circular orbits of radii and . The ratio of their angular momenta is

4. The following table compares two speeds at the same orbital radius around the same planet.

The correct comparison is

5. The negative sign in mainly indicates that

6. At Earth’s equator, the approximate reduction in effective due to rotation is . Using and , the reduction is closest to

7. A graph of against for a point mass lies below the axis and rises toward as increases. The gravitational field magnitude at a point is related to the graph by

8. Early observations of planets were not enough by themselves to give a force law because they mainly described

9. A book resting on a table experiences Earth’s gravitational pull downward and the table’s normal reaction upward. The gravitational force differs from the normal reaction because gravitational force

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

11. A notebook line says, “At height , use .” The main error in this line is that it uses

12. A planet has uniform density and radius . Its surface gravity is

13. A student compares , , and for satellites at larger and larger circular orbital radii. The correct trend is

14. Inertial mass of a body is best connected with

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

16. A point mass is fixed in space. If the distance from is doubled, the gravitational field magnitude becomes

17. Two planets P and Q have surface gravities and . Planet Q has times the mass of P and times the radius of P. The ratio is

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

19. The time period of a circular satellite around a planet of mass is

20. A satellite is at a height above Earth’s surface. If is the surface value, the gravitational acceleration at the satellite is

21. Two fixed masses and are separated by distance . At the point between them where the net gravitational field is zero, the gravitational potential is

22. A body of mass is on a planet where . Its weight on that planet is

23. Consider these statements about geostationary and polar satellites.
I. A geostationary satellite has an equatorial orbit.
II. A polar satellite appears permanently fixed above one point on the equator.
III. A geostationary satellite has period nearly equal to Earth’s rotation period.
IV. A polar satellite can be useful for mapping and weather observation over many regions.
The suitable choice is

24. 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

25. The best reason a pencil released inside an orbiting spacecraft appears to float beside an astronaut is that the pencil

26. A mass is moved slowly from distance to distance from a fixed mass . The work done by gravitational force is

27. The constant for circular satellites around the same planet is

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

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

30. A graph of against depth below Earth’s surface, assuming uniform density, is expected to be

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

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

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

34. 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

35. Earth’s rotation affects the apparent value of because a body on Earth also needs

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

37. A body is taken to height above Earth and another identical body is taken to depth below Earth’s surface, where . If the decrease in weight at height is , the decrease in weight at the same depth is approximately

38. The table lists two changes in separation for the same pair of masses.

The correct signs for I and II are

39. 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

40. A body of mass is lowered slowly from Earth’s surface to a depth inside a uniform Earth. The work done by gravity during this slow inward movement is

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

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

43. Starting with and , the derived circular-orbit relation is

44. 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

45. For two fixed masses, a graph of gravitational force against should be

46. Consider the following statements about the gravitational interaction between two bodies.
I. The force on due to and the force on due to are equal in magnitude.
II. These two forces act in opposite directions.
III. The two bodies must have equal accelerations.
The suitable choice is

47. A relation is proposed for orbital speed as . A unit check shows that has the dimension of

48. The following table compares formulas and their validity conditions.

The table is

49. A body is projected vertically upward from Earth’s surface with speed less than escape speed, neglecting air resistance. Its total mechanical energy is

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