A system of 2 capacitors of capacitance `2muF` and `4muF` is connected in series across potential difference of 6 V. The electric charge and energy stored in the system are

Options

A. `1 muC` and `3 muJ`
B. `8 muC` and `24 muJ`
C. `10 muC` and `30 muJ`
D. `36 muC` and `108 muJ`

Answer

B

Explanation

`C_(1)= 2muF, C_(2)= 4muF`
In series combination the equivalent capacitance will be `C= (C_(1)C_(2))/(C_(1)+C_(2))= ((2 xx 4)/(2+4))muF= (4)/(3)muF`
Potential difference applied, V = 6 V
Electric charged stored, `Q = CV = ((4)/(3) xx 6)muC= 8muC`
Energy stored in the system, `U = (1)/(2)CV^(2)`
`= (1)/(2)xx(4)/(3) xx 10^(-6)xx (6)^(2)J= 24 muJ`