A `100W-220V` bulb is connected to 110 V source. Calculate thepower consumed by the bulb.

Explanation

Power of the bulb, `P=100W`
Operating voltage, `V=200V`
Resistance of the bulb, `R=(V^(2))/(P)=((200)^(2))/(100)=484Omega`
Actual operating voltage, `V^(1)=100V`
Therefore, power consumed by the bulb,
`P^(1)-((V^(1))^(2))/(R )=((100)^(2))/(484)=25W`.