Question

A part of a circuit in steady state along with the currents flowing in the branches,the values of resistances,etc, is shown in figure.Calculate the energy stored in the capacitor.

A. `200muJ`
B. `400muJ`
C. `600muJ`
D. `800muJ`

Answer 1

Correct Answer - D
Current in `AD = 2+1 = 3A`
Current in`DC = 3A`
Current in `CB = 1A`
p.d. between `A` and `B`
`V_(A) - 3 xx 5-3xx1-1xx2=V_(B)`
`V = V_(A)-V_(B) = 20 "Volt"`
energy stroed in capacitor
`U - 1/2 CV^(2) = 1/2 xx 4 xx 10^(-6)xx(20)^(2)`
`=800xx10^(-6)J = 800 muJ`.