When three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the…
When three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be:
60 watt
180 watt
10 watt
20 watt
Solution
The resistance of each bulb is $\frac{V^2}{P}$ $=\frac{(200)^2}{60} \Omega$ when three bulbs are connected in series then equivalent resistance is $\frac{3 \bullet(200)^2}{60}$
$\therefore \quad$ Power $P=\frac{V^2}{R_{e q}}=20 \mathrm{~W}$