Free Gravitation MCQs with Answers

265 Gravitation MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.

Newton’s law of universal gravitation relates the force between masses to their masses and separation, while gravitational field strength explains weight and orbital motion. The topic covers satellite velocity and period, escape ideas, weightlessness in free fall, and artificial gravity, which differs from ordinary gravitational attraction.

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265 questions · page 18 of 27

171. The mean density of earth is:

Moderate
  • A. 5462 kgm-3
  • B. 5462 gm-3
  • C. 5462 kgm3
  • D. None of these

Explanation: A is correct. It is a fact that the mean density of Earth is approximately 5.5 x 103 kgm-3 .

Correct answer: 5462 kgm-3

172. Acceleration due to gravity is given by the equation:

Moderate
  • A. Option A
  • B. Option B
  • C. Option C
  • D. Option D

Explanation: B is correct as per the derived formula. g= GM/R2 .

Correct answer: Option B

173. Value of acceleration due to gravity gh at height h is given by the equation:

Moderate
  • A. Option A
  • B. Option B
  • C. Option C
  • D. Option D

Explanation: The Explanation for this question will be added soon!

Correct answer: Option B

174. The radius of earth is:

Moderate
  • A. 6400 m
  • B. 6400 km
  • C. 6400 cm
  • D. 6400 dm

Explanation: B is correct. It is a fact that the radius of the Earth is 6400 km.

Correct answer: 6400 km

175. It is a measure of the reluctance of an object to change its state of motion when force is applied:

Moderate
  • A. Mass
  • B. Inertial mass
  • C. Gravitational mass
  • D. None of the above

Explanation: B is correct. Inertia is the measure of the reluctance of an object to change its state of motion when force is applied according to the 1st law of motion.

Correct answer: Inertial mass

176. Acceleration due to gravity at a depth x is given as:

Moderate
  • A. Option A
  • B. Option B
  • C. Option C
  • D. Option D

Explanation: A is the correct option as per the derived formula.

Correct answer: Option A

177. When a body is lifted to twice earth's radius above the surface of the earth, the value of g decreases by:

Moderate
  • A. Two times
  • B. Three times
  • C. Six times
  • D. Nine times

Explanation: D is correct. g= GM/r 2 , as the distance is increased from R to 3R so g' will be =GM/9r2 As a result g' will be 9 times less than g.

Correct answer: Nine times

178. The frequency of rotation for artificial gravity is:

Moderate
  • A. Option A
  • B. Option B
  • C. Option C
  • D. Option D

Explanation: C is correct as per the derived formula, formed by using centripetal acceleration.

Correct answer: Option C

179. Freely falling bodies are in a state of:

Moderate
  • A. Rest
  • B. Static equilibrium
  • C. Dynamic equilibrium
  • D. Weightlessness

Explanation: Dis correct. Freely falling bodies are already accelerating at a 9.81 m/s2 so experience no additional force by Earth and hence feel weightless.

Correct answer: Weightlessness

180. What is produced by spinning the spaceship around its own axis with a certain frequency which can provide centripetal force equal to the force of gravity at that point?

Moderate
  • A. Weightlessness
  • B. Artificial gravity
  • C. Vacuum
  • D. None of the above

Explanation: B is correct. By spinning the spaceship around its own axis with a certain frequency which can provide centripetal force equal to the force of gravity, we can produce artificial gravity which reduces the feeling of weightlessness.

Correct answer: Artificial gravity