JEE Main & Advanced
Sample Paper
JEE Main - Mock Test - 35
question_answer
The supply voltage to room is 120V. The resistance of the lead wires is 60. A 60 W bulb is already switched on. What is the decrease of voltage across the bulb, when a 240 W heater is switched on in parallel to the bulb?
A)zero
B)2.9 volt
C)13.3 volt
D)10.04 volt
Correct Answer:
D
Solution :
Voltage across bulb before heater is switched on, Voltage across bulb after heater is switched on, Hence decrease in voltage (approximately)