1.

If voltage across a bulb rated 220 volt-100 watt drops by `2.5 %` of its value, the percentage of the rated value by which the power would decrease isA. 0.2B. 0.025C. 0.05D. 0.1

Answer» Correct Answer - C
`"Power", R=(V^(2))/(R)`
As the resistance of the bulb is constant
`therefore (DeltaP)/(P)=(2DeltaV)/(V)`
`"% decrease in power"=(DeltaP)/(P)xx100=(2DeltaV)/(V)xx100`
`2xx2.5%=5%`


Discussion

No Comment Found

Related InterviewSolutions