Assertion (A): | Improper banking of roads causes wear and tear of tyres. |
Reason (R): | The necessary centripetal force in that event is provided by the force of friction between the tyres and the road. |
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 rocket moves forward by pushing the surrounding air backward. |
Reason (R): | It derives the necessary thrust to move forward according to Newton's first law of 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. |
Assertion (A): | On a banked curved track, the vertical component of normal reaction provides the necessary centripetal force. |
Reason (R): | Centripetal force is not always required for turning. |
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 rocket works on the principle of conservation of linear momentum. |
Reason (R): | Higher is the velocity, smaller is the pressure and vice-versa. |
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): | In a non-uniform circular motion, the acceleration of the particle is equal to the vector sum of the tangential acceleration and the centripetal acceleration. |
Reason (R): | The two accelerations are perpendicular to each other. |
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): | In a non-uniform circular motion, there are two types of accelerations i.e. centripetal and tangential. |
Reason (R): | Tangential acceleration is responsible to change the speed of the particle moving in a circular 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. |
Assertion (A): | On a rainy day, it is difficult to drive a car or a bus at a high speed. |
Reason (R): | The value of the coefficient of friction is lowered when the surface is wetted. |
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 cyclist leans inwards while taking a turn, while a man sitting in a car leans outward on a curve. |
Reason (R): | Centripetal acceleration is acting towards the centre of the curve. |
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 driver in a vehicle moving at a constant speed on a straight road is in a non-inertial frame of reference. |
Reason (R): | A reference frame in which Newton's law of motion is applicable is non-inertial. |
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 use of ball bearings between two moving parts of a machine is a common practice. |
Reason (R): | Ball bearings reduce vibrations and provide good stability. |
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. |