According to Joule #39;s law of heating,

Your Ultimate Guide to JEE & NEET Question Solutions

According to Joule's law of heating, heat produced $H = {I^2}\,Rt$, where I is current, $R$ is resistance and $t$ is time. If the errors in the measurement of $I, R$ and t are $3\%, 4\% $ and $6\% $ respectively then error in the measurement of $H$ is

A

$ \pm 17\%$

B

$ \pm 16\%$

C

$ \pm 19\%$

D

$ \pm 25\%$

According to Joule's law of heating, heat produced $H = {I^2}\,Rt$, where I is current, $R$ is resistance and $t$ is time. If the errors in the measurement of $I, R$ and t are $3\%, 4\% $ and $6\% $ respectively then error in the measurement of $H$ is

$H = {I^2}R\,t$

$\therefore \,\,\,\frac{{\Delta H}}{H} \times 100 = \left( {\frac{{2\Delta I}}{I} + \frac{{\Delta R}}{R} + \frac{{\Delta t}}{t}} \right) \times 100$

$ = (2 \times 3 + 4 + 6)\% $ $ = 16\% $