MCQOPTIONS
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MCQOPTIONS
This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
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» C. decrease 90 times | |
| 2. |
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 velocity 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» D. Equal to that of the earth | |
| 3. |
A particle is kept at a distance R above the earth s surface. What is the minimum speed with which it should be projected so that it does not return? |
| A. | [(G*M)/(4*R)]<sup>1/2</sup> |
| B. | [(G*M)/(2*R)]<sup>1/2</sup> |
| C. | [(G*M)/R] <sup>1/2</sup> |
| D. | [(2*G*M)/R]<sup>1/2</sup> |
| Answer» D. [(2*G*M)/R]<sup>1/2</sup> | |
| 4. |
A planet as a radius R and density P . The escape velocity of this planet is _____ |
| A. | directly proportional to P |
| B. | inversely proportional to P |
| C. | directly proportional to P<sup>1/2</sup> |
| D. | inversely proportional to P<sup>1/2</sup> |
| Answer» D. inversely proportional to P<sup>1/2</sup> | |
| 5. |
The escape velocity for an object to leave the surface of the earth does not depend on its size, shape, mass or direction of projection of the body. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 6. |
The escape velocity of a planet depends on the radius of its orbit around the parent star.
|
| A. | False |
| Answer» C. | |
| 7. |
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» B. 0.7 times | |
| 8. |
A black hole is called so because it is a hypothetical object. |
| A. | True |
| B. | False |
| Answer» C. | |
| 9. |
The escape velocity at the event horizon of a black hole is 3 108 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? |
| A. | 12.15 x 10<sup>-30</sup> kg |
| B. | 12.15 x 10<sup>30</sup> kg |
| C. | Infinity |
| D. | Cannot be determined |
| Answer» C. Infinity | |
| 10. |
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» B. the mean velocities of atmospheric gas molecules which is greater than that of the earth s escape velocity | |
| 11. |
The escape velocity of the earth is v . If an object is thrown vertically upwards with a velocity kv , what is the speed of the object at infinity? |
| A. | v/(k<sup>2</sup>-1)<sup>1/2</sup> |
| B. | v(k<sup>2</sup>-1)<sup>1/2</sup> |
| C. | v<sup>2</sup>/(k<sup>2</sup>-1) |
| D. | v<sup>2</sup> (k<sup>2</sup>-1) |
| Answer» C. v<sup>2</sup>/(k<sup>2</sup>-1) | |
| 12. |
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 the acceleration due to gravity? |
| A. | R/2 |
| B. | R |
| C. | 2R |
| D. | 4R |
| Answer» C. 2R | |
| 13. |
The escape velocity of an object from the surface of the planet does not depend on the mass of the object. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 14. |
What is the minimum velocity required for an object of mass m to escape the gravitational pull of a planet of mass M and radius R from its surface? |
| A. | [(G*M)/R]<sup>1/2</sup> |
| B. | [(2*G*M)/R] <sup>2</sup> |
| C. | [(G*M*m)/R]<sup>1/2</sup> |
| D. | [(2*G*M)/R]<sup>1/2</sup> |
| Answer» E. | |
| 15. |
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 velocities of the two planets is _____ |
| A. | (pr)<sup>1/2</sup> |
| B. | (p/r)<sup>1/2</sup> |
| C. | (pr) |
| D. | (p/r) |
| Answer» B. (p/r)<sup>1/2</sup> | |