Question

The side of cubical box when measured with a vernier callipers is $2.50cm$. The vernier constant is $0.01cm$. The maximum possible error in the area of the side of the block is -

• A. $\pm 0.01c{m}^2$
• B. $\pm 0.02c{m}^2$
• C. $\pm 0.05c{m}^2$
• D. $\pm 0.10c{m}^2$

Answer 1

The correct option is C $\pm 0.05c{m}^2$

$\begin{array}{c}a=2\text{.5cm}\\ da=\text{0.01cm}\end{array}$

$\begin{array}{cc}\text{Area of one side}& =a\times a\\ A& =a^2\end{array}$

$\begin{array}{c}\text{Diff. both side}\\ dA=2ada\\ dA=2\times 2.5\times 0.01\\ dA=0.05cm\end{array}$