Class 11 Physics — Chapter 8: Gravitation Online Test

1. The gravitational self-energy of a uniform sphere of density and radius is:

2. If Earth’s radius is , what is the orbital radius of a geostationary satellite?

3. Why is gravitational potential always negative?

4. Inside a spherical shell of uniform mass distribution, the gravitational field is:

5. How does weightlessness assist in medical research in space?

6. When will a passenger in a lift feel weightless?

7. Which communication benefit is specific to geostationary satellites compared to low Earth orbit satellites?

8. What is the total mechanical energy of a satellite in terms of its potential energy ?

9. If the gravitational constant were larger, how would it affect the potential energy of a satellite?

10. What is the expression for the kinetic energy of a satellite in circular orbit of radius ?

11. Which force is responsible for holding galaxies together?

12. If the semi-major axis of a planet’s orbit is doubled, its orbital period will:

13. Which mathematical relation combines Newton’s Law of Gravitation with Kepler’s Third Law?

14. Which application of Kepler’s laws helps in predicting eclipses and transits?

15. In the formula , what does represent?

16. Why is the inverse-square law form essential in the gravitational formula?

17. Why is called “universal”?

18. Why is called a universal constant?

19. What is the gravitational constant commonly known as?

20. Why was Cavendish’s experiment considered groundbreaking?

1. Application of Kepler’s Third Law to moons of Jupiter allowed astronomers to:

2. Which physical constant can be determined by applying Newton’s form of Kepler’s Third Law to planetary data?

3. The gravitational self-energy of a uniform sphere of density and radius is:

4. Which type of orbit do polar satellites generally follow?

5. Escape speed is derived by equating which two forms of energy?

6. Which of the following is NOT a purpose of artificial satellites?

7. Which planet requires the greatest energy to launch a spacecraft?

8. Which application of weightlessness is directly used in protein crystal growth research?

9. Which of the following celestial bodies typically has the highest orbital eccentricity?

10. Why does decrease linearly with depth?

11. At what height above Earth’s surface will become of its surface value?

12. What is one major limitation of geostationary satellites despite their many advantages?

13. A uniform solid sphere has mass and radius . Work required to disperse the sphere into space (binding energy) is:

14. If altitude , what approximate formula can be used for ?

15. If a solid sphere is broken into two equal halves, the ratio of total self-energy after breaking to the original self-energy is approximately:

16. What is the definition of escape speed from a planet’s surface?

17. What happens to total mechanical energy of a satellite in elliptical orbit?

18. The kinetic energy of a satellite depends on:

19. Which is the correct statement of the Law of Universal Gravitation?

20. Which of the following was historically one of the first practical applications of Kepler’s laws?

21. If the value of at Earth’s surface is , what will it be at a height equal to Earth’s radius ()?

22. Why is gravitational self-energy important in astrophysics?

23. Which of the following is an Earth observation satellite?

24. Why are units and dimensions of important in physics?

25. When a body is lifted against gravity, its gravitational potential energy:

26. For a point inside a uniform solid sphere at distance from the center, the gravitational field is:

27. Which condition must be satisfied for a body to escape Earth’s gravitational field?

28. Which of the following technologies directly depends on understanding gravitation?

29. The gravitational self-energy of a star of mass and radius (Sun approx.) is:

30. Which of the following calculations would be impossible without knowing ?

1. The gravitational force between two bodies will become four times if:

2. Which of the following is an example of a navigation satellite?

3. Which of the following space technologies directly depends on calculations from universal gravitation?

4. What is the dimensionless nature of the gravitational constant ?

5. Why does a diver jumping off a high diving board feel weightless momentarily?

6. What is the SI unit of gravitational potential energy?

7. Which of the following is the correct dimensional formula for ?

8. How does variation of affect aviation and space travel?

9. If the density of a sphere is doubled but its radius remains the same, how does the gravitational self-energy change?

10. What is the connection between escape speed and black holes?

11. If the radius of a planet shrinks to half while keeping the mass constant, how does its gravitational self-energy change?

12. Which law explains why planets revolve around the Sun in elliptical orbits?

13. In Newton’s law, why is called the “scaling factor”?

14. The ratio of self-energy of Earth to that of Moon is approximately (take , ):

15. At high mountains, why does water boil at a lower temperature?

16. The orbital velocity of a satellite at a distance from Earth’s center is:

17. How does weightlessness help in biological experiments aboard the ISS?

18. The Second Law implies that the force acting on a planet is:

19. The gravitational pull of the Moon is mainly responsible for:

20. What is the altitude of a geostationary satellite approximately?

21. What is the dimensional formula of ?

22. What is the physical significance of escape speed in terms of gravitational potential energy?

23. If the radius of a planet is doubled but its mass remains the same, the new gravitational self-energy becomes:

24. If the inclination of a satellite is not zero, the satellite will:

25. Gravitational force is responsible for which of the following cosmic structures?

26. Why is escape speed important in understanding planetary atmospheres?

27. The effective acceleration due to gravity at the equator is given by:

28. Which of the following is an advantage of polar satellites over geostationary satellites?

29. Which of the following statements about gravitational force is correct?

30. What happens to escape speed if potential energy is doubled (keeping radius constant)?

31. How does escape speed affect the possibility of human colonization on other planets?

32. If a lift falls freely under gravity, passengers inside will experience:

33. Why can hot hydrogen escape from Earth’s upper atmosphere while oxygen and nitrogen remain bound?

34. Why are polar satellites preferred for mapping and cartography?

35. What is the relation between orbital speed and escape speed at the same distance ?

36. Which of the following is NOT a purpose of artificial satellites?

37. Which of the following best explains why Newton called his law “universal”?

38. The perihelion of Earth occurs in:

39. Why is the gravitational self-energy of a solid sphere negative?

40. Which of the following is a direct observational consequence of Kepler’s Second Law?

41. Kepler’s laws were derived theoretically by Newton using which fundamental law?

42. Two identical planets each of mass and radius merge to form one spherical planet of radius . Ratio of new self-energy to that of one original planet is:

43. What is the definition of escape speed from a planet’s surface?

44. Which formula directly relates work done by gravitational force to potential energy?

45. Which of the following is a necessary condition for experiencing weightlessness?

46. In the gravitational formula, what do and represent?

47. In the formula , what does represent?

48. How does gravitational self-energy scale with mass and radius ?

49. Which polar satellite application is crucial for climate change research?

50. If gravitational potential energy of Earth-satellite system is , how much energy is required to move the satellite to infinity?