Electric Dipole - Practice Questions & MCQ

An electric dipole is a system of two equal and opposite point charges separated by a very small and finite distance.

Below is the figure showing an electric dipole consisting of two equal and opposite point charges $-q$ and $+q$ separated by a small distance $2 l$.

Dipole moment- The strength of an electric dipole is measured by a vector quantity known as electric dipole moment. Its magnitude is equal to the product of the magnitude of either charge and the distance between the two charges,

i.e. for the dipole, as shown in the above figure dipole moment is given as

$
(\vec{P})=q(\overrightarrow{2 l})
$

And its direction is along the line from $-q$ to $+q$.
Its $\mathrm{S} . \mathrm{I}$ unit is C-m
and its cgs unit is Debye ( 1 Debye $\left.=3.3 \times 10^{-30} \mathrm{C}-\mathrm{m}\right)$

The axial line of dipole- A line passing through the negative and positive charges of the electric dipole is called the axial line of the electric dipole.

Centre of dipole- The midpoint of the line joining the two charges is called the centre of the dipole.

Equatorial line- An equatorial line of a dipole is the line perpendicular to the axis of the dipole and passing through the Centre of the dipole.