Question

The heat generated in a circuit is given by $Q=i^{2}Rt$, where $i$ is current, $R$ is resistance and t is time. If the percentage errors in measuring $i,R$ and $t$ are $2$%, $1$% and $1$% respectively, then the maximum error in measuring heat will be :

• A. 2%
• B. 3%
• C. 4%
• D. 6%

Answer 1

The correct option is D 6%

$Y=i^{2}RT$
$\Rightarrow \frac{△Y}{Y}=2\frac{△i}{i}+\frac{△R}{R}+\frac{△T}{T}$
$=2\left(2\right)+1+\left(1\right)$
$=6$%