Question #deecf

1 Answer
Feb 11, 2016

Answer:

Only (A) and (B) bulbs will glow. Option 3 is the correct choice.

Explanation:

Voltage applied is AC 4V peak. It implies that r.m.s voltage of #4/sqrt 2#V is the output of the shown generator. This is about 2.8 V, r.m.s across bulbs.

Better Regulated voltage is applied across LED (C) due to full wave rectifier being present between the voltage source and the LED. But it can not emit light as it is reversed biased.

It is presumed that the voltage applied is within the rating of the bulbs so as not to damage the bulbs.

Given figure:

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