Question

In a factory, due to a sudden strike the work usually done in a day took a longer time. Which of the following happened?
A. Power increased
B. Power decreased
C. Energy increased
D. None of these

Answer 1

Hint: In this question we have to understand the statement and use the concept of work done, power and energy to solve the problem.

Complete step by step answer:
We know that when work is done by a body or a system, we can calculate the power of the body or the system. The power of a system is given as work done in one unit of time.
For this question we have to assume the factory and the workers to be a system who does work.
Since due to the sudden strike among the workers, the work which was to be done in a day took longer. Therefore, the duration of the work done is increased than the usual case.
Power of the system is directly proportional to the work done by the system and inversely proportional to the time taken by the system to do the work. The work done in the usual case is equal to the work done during strike but the time taken by the workers to do the work was increased and because power is inversely proportional to the time taken, if the time increases then the power will decrease. Hence, option B seems to be the correct answer but before we finalize, we have to consider the energy factor also.
The energy of a system is equal to the work done by the system or work done on the system, since the work done by the worker is the same and only the time has increased. The change of the time has no effect on the energy of the system.

Therefore, we can now say that the final correct answer is option (B).

Note:
The questions like these require mental aptitude from the students. These questions require students to understand the scenario from the word problem and apply the necessary concept and find the solution.