Electric Dipole : Electric Dipole Moment

Define electric dipole moment and write its SI unit.

The tyres of aircrafts are not made of ordinary rubber (which is an insulator) but of a special rubber which is slightly conducting. Why?

Write the dimensions of electric dipole moment.

What is an electric dipole? Give two examples.

An electric dipole, when held at ${30}^{\circ }$ with respect to a uniform electric field of ${10}^4 \raisebox{1ex}{$\mathrm{N}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{C}$}\right.$, experiences a torque of  $9\times {10}^{-26} \mathrm{Nm}$. Calculate the moment of the dipole.

Two point-charges of $+1 \mathrm{\mu C}$ and $-1 \mathrm{\mu C}$are kept at a distance of $2 \mathrm{cm}$. They form an electric dipole. This dipole is situated in a uniform electric; field of $1\times {10}^5 {\mathrm{NC}}^{-1}$, with dipole moment vector p making an angle of ${30}^{\circ }$ with the field. Calculate (i) the magnitude of electric dipole moment. 

A system has two charges $q_{\mathrm{A}}=+0.25 \mathrm{\mu C}$ and $q_{\mathrm{B}}=-0.25 \mathrm{\mu C}$ at points $\mathrm{A} (0, 0, -15 \mathrm{cm})$ and $\mathrm{B} (0, 0, +15 \mathrm{cm})$, respectively. Find the total charge and electric dipole moment of the system.

Two charges, one $+5 \mathrm{\mu C}$ and other $-5 \mathrm{\mu C}$ are placed $1 \mathrm{mm}$ apart. Calculate the dipole moment.