Question

Equal charges `q` are placed at the vertices `A` and `B` of an equilatral triangle `ABC` of side `a`. The magnitude of electric field at the point `C` is
A. `(q)/(4piepsilon_(0)a^(2))`
B. `(sqrt(2)q)/(4piepsilon_(0)a^(2))`
C. `(sqrt(3)q)/(4piepsilon_(0)a^(2))`
D. `(q)/(2piepsilon_(0)a^(2))`

Answer 1

Correct Answer - c
`|E_(A)|=|E_(B)|=k.(q)/(a^(2))`

So, `E_(n et)= sqrt(E_(A)^(2)+E_(B)^(2)+2E_(A)E_(B) cos 60^(@))`
`= (sqrt(3)k.q)/(a^(2))`
`implies E_(n et)= (sqrt(3)q)/(4piepsilon_(0)a^(2))`