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. `oo`
C. 27 J
D. 100 J

Answer

C

Explanation

Electrostatic PE of the system will be
`U=3xx(kxx10xx10xx10^(-12))/(10xx10^(-2))`
`=(3xx9xx10^(9)xx10^(2)xx10^(-12)xx10^(1))/(10^(2)xx10^(-2))`
`U=3xx9xx10^(9)xx10^(-9)=3xx9=27J`