Explanation:
C Let resistors A, B and C have equal resistance R.
Let $\mathrm{I}$ be the total current then the current in resistor $\mathrm{A}$ is I and in resistor $\mathrm{B}$ and $\mathrm{C}$ are $\frac{\mathrm{I}}{2}$ So,
$\text { Heat produced in resistor } \mathrm{A} \text { is, }$
$\mathrm{H}_{\mathrm{A}}=\mathrm{I}^{2} \mathrm{R}$
Heat produced in resistor $\mathrm{B}$ is
$\mathrm{H}_{\mathrm{B}}=\left(\frac{\mathrm{I}}{2}\right)^{2} \mathrm{R}=\frac{\mathrm{I}^{2} \mathrm{R}}{4}$
Heat produced in resistor $\mathrm{C}$ is,
$\mathrm{H}_{\mathrm{C}}=\frac{\mathrm{I}^{2} \mathrm{R}}{4}$
Hence, it is clear that the heat produced will be maximum in A.
