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. Why does the Sun not collapse under its own gravity?

2. The statement “Every object in the Universe attracts every other object with a force” was first mathematically given by:

3. What is the expression for the total mechanical energy of a satellite in circular orbit of radius ?

4. At what approximate altitude above Earth’s surface are geostationary satellites placed?

5. Why do astronauts need to secure liquids in sealed containers during weightlessness?

6. Which expression represents the gravitational field due to a point mass at a distance ?

7. If the gravitational field at a point is , what does it mean?

8. At which location on Earth’s surface is the value of maximum?

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

10. How does gravitation affect tides on Earth?

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

12. What was the historical significance of Cavendish’s experiment beyond finding ?

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

14. Which principle is applied in deriving the expression for below Earth’s surface?

15. Which of the following is the primary use of communication satellites?

16. The gravitational self-energy of a uniform solid sphere of mass and radius is given by:

17. If the radius of Earth increases while its mass remains the same, what happens to ?

18. Why is the escape speed from the Moon much lower than from Earth?

19. Which planet takes the longest time to orbit the Sun?

20. Which formula gives the value of at a depth below Earth’s surface (assuming uniform density)?

21. Which condition best explains why astronauts feel weightless in a spacecraft orbiting Earth?

22. How many geostationary satellites are typically required to cover the entire Earth’s surface (except polar regions)?

23. Which of the following is a practical example of weightlessness on Earth?

24. For a star of density and radius , binding energy is proportional to:

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

26. Which statement is correct about inside and outside Earth?

27. What is the relation between conservation of energy and escape velocity?

28. Which statement correctly describes the work done by gravity when an object falls freely?

29. For a planet of radius and density , escape speed can be expressed as:

30. What was India’s first artificial satellite?

1. Why is considered the least precisely known of the fundamental physical constants?

2. Which force provides the centripetal force for satellites orbiting Earth?

3. The kinetic energy of a satellite depends on:

4. Which factor directly affects the magnitude of potential energy of an orbiting satellite?

5. At a point inside a uniform spherical shell of mass , the gravitational potential is:

6. Why are polar satellites effective in disaster management?

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

8. Which equation explains why objects inside an orbiting satellite experience weightlessness?

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

10. Kepler’s Second Law can be derived from which principle of physics?

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

12. Which equation helps explain why astronauts float inside the ISS?

13. What is the SI unit of gravitational potential?

14. For a uniform density sphere, the gravitational potential at center is related to self-energy by:

15. What is the escape speed from the Moon’s surface? (Moon’s mass , radius )

16. What is the angular velocity of a geostationary satellite?

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

18. Which of the following statements is true about the potential energy of a satellite?

19. If the orbital speed of a satellite close to Earth’s surface is about 7.9 km/s, what will be the escape speed from Earth?

20. For a uniform sphere, which integral correctly represents gravitational self-energy?

21. Which Kepler’s law is essential for predicting the varying speed of comets in their orbits?

22. Which condition must be satisfied for a satellite to remain in circular orbit?

23. If Earth is approximated as a uniform solid sphere of mass and radius , the gravitational self-energy is closest to:

24. Why does escape speed not depend on the direction of projection?

25. Which relation is used in a free-fall experiment to calculate if a body falls a distance in time ?

26. A satellite with an inclination of is in:

27. Which graph correctly represents variation of gravitational potential with distance from a point mass?

28. Which satellite has higher orbital velocity, geostationary or polar?

29. What is the formula for effective gravity at latitude considering Earth’s rotation?

30. What physical principle allowed Cavendish to measure such a tiny force in his experiment?

31. Why is the product important in the formula?

32. What is the gravitational potential at a distance from a point mass ?

33. Which of the following is a direct example of universal gravitation in everyday life?

34. Which of the following scientific fields directly benefits from studying variation of ?

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

36. Which experiment is commonly used to measure the value of near Earth’s surface?

37. Which of the following practical applications depends on knowing the variation of with altitude?

38. If the orbital radius of a satellite increases, its orbital velocity will:

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

40. Which application of variation is used in mineral and oil exploration?

41. Why does decrease linearly with depth?

42. If Earth’s mass is and radius is , what is Earth’s escape speed? ()

43. Which condition best explains why astronauts feel weightless in a spacecraft orbiting Earth?

44. In elliptical orbits, how does the kinetic and potential energy of a satellite vary?

45. The main difference in application between geostationary and polar satellites is:

46. Why are polar satellites suitable for environmental studies?

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

48. On which two factors does escape speed of a planet primarily depend?

49. Which type of satellite is used for navigation purposes?

50. Why can Earth’s atmosphere not extend indefinitely into space?