The charge per unit length of the four quadrant of the ring is `2 lambda, -2lambda, lambda` and `-lambda` respectively. The electric field at the centre is:

Options

A. `(-lambda)/(2piepsilon_(0)R)hat(i)`
B. `lambda/(2pi epsilon_(0)R) hat(j)`
C. `(sqrt(2)lambda)/(4 pi epsilon_(0)R) hat(i)`
D. None

Answer

A

Explanation

`E_("net")=sqrt(2)E=sqrt(2)[(lambdasqrt(2))/(4pi in_(0)R)]rArr vec(E)=(lambda(-hat(i)))/(2pi in_(0)R)`