Electric field at center O of a semicircle of radius a having linear charge density λ given as:
1
\(\frac{{2\lambda }}{{{\varepsilon _0}a}}\)
2
\(\frac{{\lambda \pi }}{{{\varepsilon _0}a}}\)
3
\(\frac{\lambda }{{2\pi {\varepsilon _0}a}}\)
4
\(\frac{\lambda }{{\pi {\varepsilon _0}a}}\)