Assertion (A): | The angular velocity of a planet orbiting around the sun increases when it is nearest to the sun. |
Reason (R): | Angular momentum of a body is proportional to angular velocity. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | A body becomes weightless at the centre of the earth. |
Reason (R): | As the distance from the centre of earth decreases, acceleration due to gravity increases. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The binding energy of a satellite depends upon the mass of the satellite. |
Reason (R): | Binding energy is the negative value of the total energy of a satellite. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The speed of revolution of an artificial satellite revolving very near the earth is 8 kms-1. |
Reason (R): | Orbital velocity of a satellite becomes independent of the height of the satellite. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The length of the day is slowly increasing. |
Reason (R): | The dominant effect causing a slowdown in the rotation of the earth is the gravitational pull of other planets in the solar system. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion(A): | A planet moves faster when it is closer to the sun in its orbit and vice-versa. |
Reason(R): | Orbital velocity in the orbit of the planet is constant. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The comets do not obey Kepler's law of planetary motion. |
Reason (R): | The comets do not have elliptical orbits. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The square of the period of revolution of a planet is proportional to the cube of the semi-major axis of its elliptical orbit. |
Reason (R): | Sun's gravitational field is inversely proportional to the square of its distance from the planet. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | At the pole, the value of acceleration due to gravity (g) is greater than that at the equator. |
Reason (R): | Earth rotates on its axis in addition to revolving around the sun.- |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The time period of the revolution of a satellite around a planet is directly proportional to the radius of the orbit of the satellite. |
Reason (R): | Artificial satellites do not follow Kepler's law of planetary motion. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |