Current Electricity Charging Discharging Of Capacitors Question 471

Question: An electric bulb of 100 watt is connected to a supply of electricity of 220 V. Resistance of the filament is

[EAMCET 1981, 82; MP PMT 1993, 97]

Options:

A) $ 484,\Omega $

B) $ 100,\Omega $

C) $ 22000,\Omega $

D) $ 242,\Omega $

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Answer:

Correct Answer: A

Solution:

$ \frac{V^{2}}{R}=P, $

Therefore $ R=\frac{V^{2}}{P}=\frac{220\times 220}{100}=484\Omega $