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Assertion :in a chain of bulbs, 50 bulbs are joined in series. one bulb is fused now. if the remaining 49 bulbs are again connected in series across the same supply then light gets decreased in the room.

reason: the net resistance of 49 bulbs will be less then 50 bulbs.

A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1
B. Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1
C. Statement-1 is True, Statement-2 is True
D. Statement-1 is False , Statement-2 is True

User Jpoppe
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1 Answer

3 votes

Final answer:

The light dims when one bulb in a series of 50 burns out and the remaining are reconnected because the voltage across each bulb decreases, thus reducing their power output. The net resistance being lower for 49 bulbs is true but not the cause of dimming.

Step-by-step explanation:

The assertion that light gets decreased when one bulb in a series of 50 burns out and the remaining 49 bulbs are reconnected in series across the same supply is true. When bulbs are connected in series, the total resistance of the circuit is the sum of the individual resistances of each bulb. Hence, with one less bulb, the total resistance of the circuit decreases.

However, Statement-2, which states that the net resistance of 49 bulbs will be less than that of 50 bulbs, is also true but is not the correct explanation for the dimming of the light. The actual reason why the light gets decreased is that with one less bulb, the total voltage across each remaining bulb decreases, reducing the power output of each bulb according to the equation P=V2/R where P is power, V is voltage, and R is resistance. Thus, the correct option is B: Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1.

User Tadej Vengust
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