Question

A iron bar of length $l$ cm and cross section $A$ $c{m}^2$ is pulled by a force of $F$ dynes iron ends so as to produce an elongation $\Delta l$ cm. Which of the following statement is correct?

• A. Elongation is inversely proportional to length
• B. Elongation is directly proportional to cross section $A$
• C. Elongation is inversely proportional to $A$
• D. Elongation is directly proportional to Young's module

Answer 1

The correct option is C Elongation is inversely proportional to $A$

$\Delta l=\frac{FL}{AY}$
Thus, extension is inversely proportional to area. Only C statement is correct