Question

A force $\overrightarrow{F}$ is applied on a square plate of length L. If the percentage error in the determination of L is 3% and in F is 4%, the permissible error in the calculation of pressure is.

• A. 13%
• B. 10%
• C. 7%
• D. 12%

Answer 1

The correct option is B 10%

Pressure $P=\frac{F}{A}=\frac{F}{L^2}$

Permissible error in pressure $\frac{\Delta P}{P}\times 100=\frac{\Delta F}{F}\times 100+2\times \frac{\Delta L}{L}\times 100$

$⟹$ $\frac{\Delta P}{P}\times 100=4+2\times 3=10$ %