A conducting sphere $A$ of radius $a$, with charge $Q$, is placed concentrically inside a conducting shell $B$ of radius $b$. $B$ is earthed. $C$ is the common centre of the $A$ and $B$.
The field is a distance $r$ from $C$, where $a \leq r \leq b,$ is $\frac{1}{{4\pi \,{\varepsilon _0}}}\,\frac{Q}{{{r^2}}}$
The potential at a distance $r$ from $C$, where $a \leq r \leq b,$ $\frac{1}{{4\pi \,{\varepsilon _0}}}\,Q\,\left( {\frac{1}{r}\, - \,\frac{1}{b}} \right)$
The potential difference between $A$ and $B$ is $\frac{1}{{4\pi \,{\varepsilon _0}}}\,Q\,\left( {\frac{1}{a}\, - \,\frac{1}{b}} \right)$
all of the above
Two conducting spheres of radii $5\, cm$ and $10\, cm$ are given a charge of $15\,\mu C$ each. After the two spheres are joined by a conducting wire, the charge on the smaller sphere is.......$\mu C$
The dielectric strength of air at $NTP$ is $3 \times {10^6}\,V/m$ then the maximum charge that can be given to a spherical conductor of radius $3\, m$ is
Assertion : In a cavity within a conductor, the electric field is zero.
Reason : Charges in a conductor reside only at its surface
‘Inside a conductor electrostatic field is zero’. Explain.
Figure shows a solid conducting sphere of radius $1 m$, enclosed by a metallic shell of radius $3 \,m$ such that their centres coincide. If outer shell is given a charge of $6 \,\mu C$ and inner sphere is earthed, find magnitude charge on the surface of inner shell is ............. $\mu C$