Concentric metallic hollow spheres of radii $R$ and $4 R$ hold charges $Q _{1}$ and $Q _{2}$ respectively. Given that surface charge densities of the concentric spheres are equal, the potential difference $V ( R )- V (4 R )$ is
$\frac{3 Q_{1}}{16 \pi \varepsilon_{0} R}$
$\frac{ Q _{2}}{4 \pi \varepsilon_{0} R }$
$\frac{3 Q _{1}}{4 \pi \varepsilon_{0} R }$
$\frac{3 Q _{2}}{4 \pi \varepsilon_{0} R }$
Calculate potential on the axis of a disc of radius $R$ due to a charge $Q$ uniformly distributed on its surface.
A spherical conductor of radius $2\,m$ is charged to a potential of $120\,V.$ It is now placed inside another hollow spherical conductor of radius $6\,m.$ Calculate the potential to which the bigger sphere would be raised......$V$
Two charged spheres of radii $10\, cm$ and $15\, cm$ are connected by a thin wire. No current will flow, if they have
Electric charges having same magnitude of electricicharge $q$ coulombs are placed at $x=1 \,m , 2 \,m , 4 \,m$, $8 \,m$....... so on. If any two consecutive charges have opposite sign but the first charge is necessarily positive, what will be the potential at $x=0$ ?
Considering a group of positive charges, which of the following statements is correct?