Two large,thin metal plates are parallel and close to each other. Their inner faces have surface charge densities of the same sign and magnitude $17.7 \times 10^{-22} \ C/m^2$. What is the electric field $E$ in the outer region of the second plate?

The region between two concentric spheres of radii '$a$' and '$b$' (see figure) has a volume charge density $\rho = \frac{A}{r}$,where $A$ is a constant and $r$ is the distance from the centre. At the centre of the spheres is a point charge $Q$. The value of $A$ such that the electric field in the region between the spheres is constant,is:

The electric field intensity $(E)$ at a distance of $3 \ m$ from a uniform long straight wire of linear charge density $0.2 \ \mu Cm^{-1}$ is

The given figure shows two parallel plates $A$ and $B$ with charge densities $+\sigma$ and $-\sigma$ respectively. The electric intensity will be zero in which region?

Consider an atom with atomic number $Z$ as consisting of a positive point charge at the centre and surrounded by a distribution of negative electricity uniformly distributed within a sphere of radius $R$. The electric field at a point inside the atom at a distance $r$ from the centre is

An electric dipole is placed on the $x$-axis in proximity to a line charge with a linear charge density of $3.0 \times 10^{-6} \, C/m$. The line charge is placed on the $z$-axis. The positive and negative charges of the dipole are at distances of $10 \, mm$ and $12 \, mm$ from the origin,respectively. If a total force of $4 \, N$ is exerted on the dipole,find the magnitude of the positive or negative charge of the dipole.