Question

Assertion :A $60W$ bulb is connected in parallel with a room heater and this combination is connected across the mains. If the $60W$ bulb is replaced by a $100W$ bulb, the heat produced by the heater will be more . BECAUSE Reason: When resistances are connected in parallel across the mains, the heat produced is inversely proportional to the resistance

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

Answer: (D)

In parallel connections voltages in all branches are same and so change in bulb will not effect heat produced in heater so assertion is incorrect.

Power = $\frac{V^2}{R}$ Power is inversely proportional to Resistance so reason is correct.