Question

In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.

Assertion: A weight lifter does no work in holding the weight up.

Reason: Work done is zero because distance moved is zero,

• A. Both assertion and reason are correct statements but the reason is the correct explanation of the assertion.
• B. Both assertion and reason are correct statements but the reason is not the correct explanation of the assertion.
• C. The assertion is correct but the reason is the wrong statement.
• D. The assertion is wrong but the reason is a correct statement.
• E. Both assertion and reason are wrong statements.

Answer 1

The correct option is A

Both assertion and reason are correct statements but the reason is the correct explanation of the assertion.

Explanation for Assertion statement:

1. Work done by the weight lifter on the weight is given by, $W=F\cdot d$ where $F$ is the force acting on the weight applied by the lifter and $d$ is the corresponding displacement.
2. The scenario described here involves a weightlifter holding up a weight.
3. A force is exerted by the weight lifter to hold up the weight. So, we have $F\ne 0$.
4. Now, when the lifter holds up the weight, no displacement of the weight is observed. The weight remains stationary. So we have,$d=0$.
5. Then we can obtain the work done by the lifter as $W=F\cdot 0=0$. So zero work is done by the lifter in holding the weight up.
6. Since, the assertion mentions that zero work is done by the weight lifter, we can confirm that the assertion is true.

Explanation for Reason statement:

1. The reason for this assertion as we obtained is that no displacement occurs.
2. This reason matches with the reason provided in the question.
3. So we conclude that the assertion and the reason behind the assertion are true and correct.

Both assertion and reason are correct statements but reason is the correct explanation of the assertion.

Hence, the correct option is A.