Question

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

• A. 1%
• B. 2%
• C. 4%
• D. 8%

Answer 1

Answer: (D)

8%

Answer 2

We have,
Pressure $=\frac{\text { Force }}{\text { Area }}=\frac{F}{L^{2}}$
$\therefore \frac{\Delta p}{p}=\frac{\Delta F}{F}+\frac{2 \Delta L}{L}$
$=4 \%+2(2 \%)=8 \%$