Which of the following is the meaning of a variable input?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → An input the amount of which can be varied
A variable input is one whose amount can be changed. In the short run, the firm changes output by changing such inputs.
Option (1) An input which cannot be varied in the short run — Incorrect. An input that cannot be varied in the short run is a fixed input.
Option (2) An input that is held constant while the other input is changed — Incorrect. An input held constant while the other changes is the fixed factor of the short run.
Option (3) An input whose amount can be changed only in the long run — Incorrect. A variable input can be changed in the short run too.
Option (4) An input the amount of which can be varied — Correct. This is its meaning.
NCERT (2026-27), Introductory Microeconomics, Glossary: “Variable input – An input the amount of which can be varied.” Glossary: “Fixed input – An input which cannot be varied in the short run is called a fixed input.” |