Mathematics In Physics Question 6
Question 6 - 2024 (31 Jan Shift 1)
If the percentage errors in measuring the length and the diameter of a wire are $0.1 \%$ each. The percentage error in measuring its resistance will be:
(1) $0.2 \%$
(2) $0.3 \%$
(3) $0.1 \%$
(4) $0.144 \%$
Show Answer
Answer: (2)
Solution:
$R=\frac{\rho L}{\pi \frac{d^{2}}{4}}$
$\frac{\Delta R}{R}=\frac{\Delta L}{L}+\frac{2 \Delta d}{d}$
$\frac{\Delta L}{L}=0.1 \%$ and $\frac{\Delta d}{d}=0.1 \%$
$\frac{\Delta R}{R}=0.3 \%$
