Question

Assertion: The power spent by a person exerting a force of 300 N in pulling a cart at a constant speed of 10 ms⁻¹ is 30 W. 

Reason: Power = Force × Velocity

= 300 × 10

= 3 kW

Options

• If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.

• If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion.

• If Assertion is true, but the Reason is false.

• If Assertion is false, but the Reason is true.

Answer 1

If Assertion is false, but the Reason is true.

Explanation:

The power spent by the person is

P = Fv

P = 300 × 10

= 3000 W

= 3 kW

So, the power is 3 kW, not 30 W. Therefore, the Assertion (A) is false.

The relation P = Force × Velocity is correct here. Therefore, the Reason (R) is true.

Hence, A is false but R is true.