Question

Two electric bulbs, each designed to operate with a power of $500$watts in $220$ volt line, are connected in series with a $110$ volt line. What will be the power generated by each bulb?

Answer 1

• Resistance $R=\frac{V^2}{Power}$ = $\frac{48400}{500}$=$96.8\Omega$
• Now net resistance when connected in series will be $96.8+96.8=193.6\Omega$

So now $power=\frac{{\text{new voltage}}^2}{\text{net resistance}}$ =$\frac{{110}^2}{193.6}=62.5watt$ so power by each bulb will be just half of irt i.e., $31.25$ $watt$