When three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them
Answer & explanation
Correct answer: option 4
$\text{Let Resistance of each bulb is R} P = \frac{V_0^2}{R}$
$\text{ Since Three bulbs are similar Voltage across each bulb is }\frac{V_0}{3}$
$ P_1 = \frac{V_0^2}{9R}$
$ P = 3P_1 = \frac{V_0^2}{3R} = \frac{P}{3} = \frac{60}{3} = 20W$