**Escape Speed MCQs and Answers** play important role in various entrance test so students can practice online Gravitation quiz to attempt these MCQ’s. Gravitation is one of the most difficult chapter to master in Physics. While solving this topic it becomes more complicated due to lengthy theory. So students often stuck at that point while writing exams like JEE, NEET etc. Students don’t know how to tackle the exam questions on Gravitation. Here you will get all the details regarding Gravity MCQs and answers. We already published the most important Questions and Answers on the Chapter Gravitation.

## Escape Speed MCQs and Answers

**1. An object is projected vertically upwards with a velocity (gr) **^{1/2}**. What is the maximum height reached**** by the object if “R” is the radius of the earth and “g” is t****he acceleration due to gravity?**

^{1/2}

a) R/2

b) R

c) 2R

d) 4R

**Answer: **b

**2****. The ratio of the radius of a planet A to that of a planet B is “r”. The ratio of acceleration due to gravity on the planets is “p”. The ratio of escape velocit****ies of the two planets is _____**

a) (pr)^{1/2}

b) (p/r)^{1/2}

c) (pr)

d) (p/r)

**Answer: **a

**3****. What is the minimum velocity required for an object of mass “m” to escape the gravitational**** pull of a planet of mass “M” a****nd radius “R” from its surface?**

a) [(G*M)/R]^{1/2}

b) [(2*G*M)/R] ^{2}

c) [(G*M*m)/R]^{1/2}

d) [(2*G*M)/R]^{1/2}

**Answer: **d

**4****. The escape**** velocity of an object from the surface of the planet does not de****pend on the mass of the object.**

a) True

b) False

**Answer: **a

**5. The escape velocity of the earth is “v”. If an object is thrown vertically upwards with a velocity “kv”, what is the s****peed of the object at infinity?**

a) v/(k^{2}-1)^{1/2}

b) v(k^{2}-1)^{1/2}

c) v^{2}/(k^{2}-1)

d) v^{2} (k^{2}-1)

**Answer: **b

**6. The earth is able to retain ****its atmosphere because of _____**

a) the mean velocities of atmospheric gas molecules which is less than that of the earth’s escape velocity

b) the mean velocities of atmospheric gas molecules which is greater than that of the earth’s escape velocity

c) the gravitational effect of the moon

d) the earth’s magnetic field

**Answer: **a

**7. The escape velocity at the event horizon of a black hole is 3×10**^{8}** m/s, i.e., the velocity of light. What is the mass of the black hole if the distance from its centre to the event horizon is**** 18km?**

^{8}

a) 12.15 x 10^{-30} kg

b) 12.15 x 10^{30} kg

c) Infinity

d) Cannot be determined

**Answer: **b

**8. A black hole is called so becau****se it is a hypothetical object.**

a) True

b) False

**Answer: **b

**9. The radius of the moon is approximately 3.7 times smaller than the radius of the earth. Assuming**** that their densities are same, what is the escape velocity**** of the moon compared to earth?**

a) 0.07 times

b) 0.7 times

c) 7 times

d) 3.7 times

Answer:

**10. The escape velocity of a planet depends on the radius of it****s orbit around the parent star.**

a) True

b) False

**Answer: **b

**11. The escape velocity for an object to leave the surface of the earth does not depend on its size****, shape, mass or direc****tion of projection of the body.**

a) True

b) False

**Answer: **a

**12. A planet as a radius “R” and density “P”. The escape v****elocity of this planet is _____**

a) directly proportional to P

b) inversely proportional to P

c) directly proportional to P^{1/2}

d) inversely proportional to P^{1/2}

**Answer: **c

**13. A particle is kept at a distance R above the earth’s surface. What is the minimum speed with which it should be projec****ted so that it does not return?**

a) [(G*M)/(4*R)]^{1/2}

b) [(G*M)/(2*R)]^{1/2}

c) [(G*M)/R] ^{½}

d) [(2*G*M)/R]^{1/2}

**Answer: **c

**14. The radius of Jupiter is approximately 11 times larger than the earth. Jupiter has a mass 316 times that of earth. What is the approximate escape velocit****y of Jupiter compared to earth?**

a) 100 times greater

b) 12 times greater

c) 5 times greater

d) Equal to that of the earth

**Answer: **c

**15. If the earth lost 99% of its mass, the escape velocity would _____**

a) increase 10 times

b) decrease 10 times

c) decrease 90 times

d) increase 90 times

**Answer:** b