• # question_answer If two bulbs of wattage 25 and 100 respectively each rated at 220 volt are connected in series with the supply of 440 volt, then which bulbs will fuse                                [MNR 1988] A)            100 watt bulb                       B)            25 watt bulb C)            None of them                      D)            Both of them

Resistance of 25 W bulb $=\frac{220\times 220}{25}=1936\,\Omega$ Its safe current $=\frac{220}{1936}=0.11\,\,amp.$ Resistance of 100 W bulb $=\frac{220\times 220}{100}=484\,\Omega$ Its safe current $=\frac{220}{484}=0.48\,\,amp.$ When connected in series to 440 V supply, then the current $I=\frac{440}{(1936+484)}=0.18\,amp.$ Thus current is greater for 25 W bulb, so it will fuse.