A dipole moment $$p$$ and moment of inertia $$I$$ is placed in a uniform electric field $$\mathbf{E}$$. If it is displaced slightly from its stable equilibrium position, the period of oscillation of dipole is

Figure shows three points $$A, B$$ and $$C$$ in a region of uniform electric field $$\mathbf{E}$$. The line $$A B$$ is perpendicular and $$B C$$ is parallel to the field lines. Then, which of the following holds good ? ($$V_A, V_B$$ and $$V_C$$ represent the electric potential at points $$A, B$$ and $$C$$, respectively)

When a soap bubble is charged?

Two metal plates are separated by $$2 \mathrm{~cm}$$. The potentials of the plates are $$-10 \mathrm{~V}$$ and $$+30 \mathrm{~V}$$. The electric field between the two plates is