Jee Main 2024 31 01 2024 Shift 1 - Question3
Question 3
If the percentage error in measuring length and diameter of a wire is $0.1 \%$ each, then the percentage error of the resistance of the wire is
(1) $0.3 \%$
(2) $0.2 \%$
(3) $0.1 \%$
(4) $0.4 \%$
Show Answer
Answer: (1)
Solution:
$R=\frac{\rho l}{A}$
$R=\frac{4 \rho l}{\pi d^{2}}$
$ \begin{aligned} \frac{\Delta R}{R} & =\frac{\Delta l}{l}+2 \frac{\Delta d}{d} \\ & =0.3 \% \end{aligned} $
BETA
