Question

Find the voltage of power supply to which a bulb of rating 200W- a 220V is connected to consume energy at the rate of 100 J/s.​

Answer 1

Answer:

voltage of power supply should be V = 155.56 volt

Explanation:

given

power of bulb P = 200 W

bulb can operate at V= 220 volt

so the resistance of bulb can be find

P = V²/R

200 = 48400/R

R = 48400/200

R = 242 ohm

now

we want to produce 100 j /s or 100 W

then

P = V²/R

100 = V²/242

V²=24200

V = 155.56 volt