Question

There are two resistances of $3\Omega$ and $5\Omega$. By connecting these resistances in (i) series and (ii) parallel to a cell, which resistance will be heated more?

Answer 1

$\left(i\right)$Heat produced is proportional to $H\alpha$ $i^{2}Rt$,

In series, equal current will flow through both resistors.hence resistor having more resistance will be heated more.

$\therefore$ In series $5\Omega$ resistor will be heated more.

$\left(ii\right)$Also heat produced is proportional to $H\alpha$ $\frac{V^2}{R}t$,

In parallel, potential difference $V$ across both resistors is same.hence resistance having less resistance will be heated more.

$\therefore$ In parallel $3\Omega$ resistor will be heated more