Four condensers each of capacity `4mF` are connected as shown in figure. `V_(P) - V_(Q) = 15` volts. The energy stored in the system is

Options

A. `2400` ergs
B. `1800` ergs
C. `3600`ergs
D. `5400`ergs

Answer

B

Explanation

Total capacitance of given system `C_(eq) = (8)/(5) muF`
`U = (1)/(2)C_(eq)V^(2) = (1)/(2) xx (8)/(5) xx 10^(-6) xx 225 = 180 xx 10^(-6) J`
`= 180 xx 10^(-6) xx 10^(7) "erg" = 1800 "erg"`