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)

$8\%$

As per question,

Error in the measurement of the force$=4\%$

Error in the measurement of the length $=2\%$

Pressure $=\frac{force}{area}=\frac{F}{L^2}$
$\therefore \frac{△p}{p}=\frac{△F}{F}+\frac{2△L}{L}=4\%+2\left(2\%\right)$

$=8\%$

So the maximum error in the measurement of the pressure is $=8\%$