Question

A capacitor of capacitance `10 muF` is charged by connecting through a resistance of `20 Omga` and battery of 20 V. What is the energy supplied by the battery?

A. Less than 2 mJ
B. 2mJ
C. More than 2 mJ
D. Cannot be predicted

Answer 1

Correct Answer - C
Energy stored in the capacitor
`=(1)/(2)CV^(2)`
` =(1)/(2) xx 10 xx10^(-6) xx (20)^(2)`
`= 5 xx 10^(-6) xx 400`
` = 2 xx 10^(-3)J`
` = 2mJ`
Also , some energy will be dissipated in resistance . So , energy supplied by battery is more than 2 m J.