Question

A current carrying conductor obeys $Oh{m}^{\prime }s$ law $(V=RI)$. If the current passing through the conductor is $I=(5\pm 0.2)A$ and voltage developed is $V=(60\pm 6)V$, then find the percentage of error is resistance, $R$

• A. 18
• B. 6
• C. 14
• D. 2

Answer 1

Answer: (C)

Given, current passing through the conductor,
$I=(5\pm 0.2)A,\Delta I=0.2A$
Voltage developed,
$V=(60\pm 6)V$
$\Rightarrow \Delta V=6V$
By Ohm's law,
$V=RI$
$R=\frac{V}{I}$
$\therefore \frac{\Delta R}{R}=\frac{\Delta V}{V}+\frac{\Delta I}{I}$
$=\frac{6}{60}+\frac{0.2}{5}$
$=0.1+0.04$
$\frac{\Delta R}{R}=0.14$
$\therefore \frac{\Delta R}{R}\times 100=0.14\times 100=14\%$