Three particles, each having a charge of `10 mu C` are placed at the coners of an equilateral triangle of side `10 cm`. The electrostatic potential energy of the system is (Given `(1)/(4pi epsilon_(0)) = 9 xx 10^(9)N-m^(2)//C^(2))`

Options

A. Zero
B. Infinite
C. `27 J`
D. `100 J`

Answer

C

Explanation

For pair of charge `U = (1)/(4pi epsilon_(0)).(q_(1)q_(2))/(r )`
`U_("System") = (1)/(4pi epsilon_(0)) [(10 xx 10^(-6) xx 10 xx 10^(-6))/(10//100) + (10 xx 10^(-6) xx 10 xx 10^(-6))/(10//100) + (10 xx 10^(-6) xx 10 xx 10^(-6))/(10//100)]`
`= 3 xx 9 xx 10^(9) xx (100 xx 10^(-12) xx 100)/(10) = 27 J`