Question

Three point charges `1C, 2C` and `3C` are placed at the corners of an equilaternal triangle of side `1m`. The work required to move these charges to the corners of a smaller equilaternal triangle of side `0.5 m` in two differenct ways as in fig. `(A)` and fig. `(B)` are `W_(a)` and `W_(b)` then:

Answer 1

Correct Answer - A
Work done `=U_f-U_i`
`=1/(4piepsilon_0)(1/r_f-1/r_i)[q_3q_2+q_3q_1+q_2q_1]`
=`9xx10^9(1/0.5-1/1)[(3)(2)+(3)(1)+(2)(1)]`
`=99xx10^9J`