Twenty seven drops of same size are charged at 220V each. They combine to form a bigger drop. Calculate the potential of the bigger drop.

A short electric dipole has a dipole moment of 16 $$ \times $$ 10^-9 Cm. The electric potential due to the dipole at a point at a distance of 0.6 m from the centre of the dipole, situated on a line making an angle of $$60^\circ $$ with the dipole axis is :

$$\left( {{1 \over {4\pi {\varepsilon _0}}} = 9 \times {{10}^9}N{m^2}/{C^2}} \right)$$

In a certain region of space with volume 0.2 m³, the electric potential is found to be 5 V throughout. The magnitude of electric field in this region is :

A spherical conductor of radius 10 cm has a charge of 3.2 $$ \times $$ 10^-7 C distributed uniformly. That is the magnetude of electric field at a point 15 cm from the centre of the sphere?
$$\left( {{1 \over {4\pi {\varepsilon _0}}} = 9 \times {{10}^9}N{m^2}/{c^2}} \right)$$