Three charges each of magnitude $q$ are placed at the corners of an equilateral triangle, the electrostatic force on the charge placed at the center is (each side of triangle is $L$)
Zero
$\frac{1}{{4\pi {\varepsilon _0}}}\frac{{{q^2}}}{{{L^2}}}$
$\frac{1}{{4\pi {\varepsilon _0}}}\frac{{3{q^2}}}{{{L^2}}}$
$\frac{1}{{12\pi {\varepsilon _0}}}\frac{{{q^2}}}{{{L^2}}}$
For regular pentagon system shown in figure, find force on $q_0$
Two similar spheres having $ + \,q$ and $ - \,q$ charge are kept at a certain distance. $F$ force acts between the two. If in the middle of two spheres, another similar sphere having $ + \,q$ charge is kept, then it experience a force in magnitude and direction as
$12$ positive charges of magnitude $q$ are placed on a circle of radius $R$ in a manner that they are equally spaced. A charge $Q$ is placed at the centre, if one of the charges $q$ is removed, then the force on $Q$ is
The ratio of coulomb's electrostatic force to the gravitational force between an electron and a proton separated by some distance is $2.4 \times 10^{39}$. The ratio of the proportionality constant, $K=\frac{1}{4 \pi \varepsilon_0}$ to the Gravitational constant $G$ is nearly (Given that the charge of the proton and electron each $=1.6 \times 10^{-19}\; C$, the mass of the electron $=9.11 \times 10^{-31}\; kg$, the mass of the proton $=1.67 \times 10^{-27}\,kg$ ):
Four point $+ve$ charges of same magnitude $(Q)$ are placed at four corners of a rigid square frame as shown in figure. The plane of the frame is perpendicular to $Z$ axis. If a $-ve$ point charge is placed at a distance $z$ away from the above frame $(z<< L)$ then