Electric field at centre $O$ of semicircle of radius $a$ having linear charge density $\lambda$ given is given by
$\frac{\lambda }{{2\pi {\varepsilon _0}a}}$
$\frac{\lambda }{{2\pi {\varepsilon _0}{a^2}}}$
$\frac{\lambda }{{4{\pi ^2}{\varepsilon _0}a}}$
$\frac{{{\lambda ^2}}}{{2\pi {\varepsilon _0}a}}$
A hollow sphere of charge does not produce an electric field at any
Two particles ${A}$ and ${B}$ having charges $20\, \mu {C}$ and $-5\, \mu {C}$ respectively are held fixed with a separation of $5\, {cm}$. At what position a third charged particle should be placed so that it does not experience a net electric force?
A charge produces an electric field of $1\, N/C$ at a point distant $0.1\, m$ from it. The magnitude of charge is
Two charges $+Q$ and $-2 Q$ are located at points $A$ and $B$ on a horizontal line as shown below.The electric field is zero at a point which is located at a finite distance
The unit of intensity of electric field is