Question

The pressure on a square plate is measured by measuring the force on the plate and the length of the sides of the plate. If the maximum error in the measurement of force and length are $4 \%$ and $2 \%$, respectively, then the maximum percentage error in the measurement of pressure is

Answer 1

$P=\frac{F}{l^{2}}$
$\therefore $ Maximum percentage error in the measurement of pressure,
$\frac{\Delta P}{P} \times 100=\frac{\Delta F}{F} \times 100+2 \times \frac{\Delta l}{l} \times 100 $
$=\frac{4}{100} \times 100+2 \times \frac{2}{100} \times 100=8 \%$