Assertion: In an elastic collision between two bodies, the energy of each body is conserved.
Reason: The total energy of an isolated system is conserved.
Assertion: A body can be at rest even when it is under the action of any number of external forces.
Reason: Vector sum of all the external forces is zero.
Assertion: In a non-uniform circular motion, the acceleration of the particle is equal to sum of the tangential acceleration and the centripetal acceleration.
Reason: The two acceleration are perpendicular to each other.
Assertion: A body can have acceleration even if its velocity is zero at that instant of time.
Reason: The body will be momentarily at rest when it reverses its direction of motion.
Assertion: Work done in moving a charge between any two points in a uniform electric field is independent of the path followed by the charge, between these points.
Reason: Electrostatic forces are non-conservative.
Given below are two statements:
Assertion (A): | In a transistor amplifier, the output voltage is always out of phase with the input voltage. |
Reason (R): | The emitter base junction is reverse biased and the base collector junction is forward biased. |
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. | (A) is false but (R) is true. |
Assertion: Heat from the sun reaches the earth by convection.
Reason: Air can be heated only by convection.
Assertion: A wire carrying an electric current has no electric field around it.
Reason: Rate of flow of electron’s in one direction is equal to the rate of flow of protons in opposite direction.