An electric dipole is formed by two particles fixed at the ends of a light rigid rod of length $l$ . The mass of each particle is m and charges are $- q$ and $+ q$ . The system is suspended by a torsionless thread in an electric field of intensity $E$ such that the dipole axis is parallel to the field. If it is slightly displaced, the period of angular motion is :
$\frac{1}{2 π} \sqrt{\frac{2 q E}{m l}}$
$2 π \sqrt{\frac{m l}{q E}}$
$2 π \sqrt{\frac{m l}{2 q E}}$
$\frac{1}{2 π} \sqrt{\frac{m l}{4 q E}}$

Question

An electric dipole is formed by two particles fixed at the ends of a light rigid rod of length $l$ . The mass of each particle is m and charges are $- q$ and $+ q$ . The system is suspended by a torsionless thread in an electric field of intensity $E$ such that the dipole axis is parallel to the field. If it is slightly displaced, the period of angular motion is :
$\frac{1}{2 π} \sqrt{\frac{2 q E}{m l}}$
$2 π \sqrt{\frac{m l}{q E}}$
$2 π \sqrt{\frac{m l}{2 q E}}$
$\frac{1}{2 π} \sqrt{\frac{m l}{4 q E}}$

Toppr Admin · Accepted Answer

We know torque on a dipole is-xA0-x3C4-P-xD7-EWhen the dipole is displaced by -x3B8-x3C4-PEsin-x3B8-The electric field tries to align the dipole in the same direction as that-xA0-of the field-xA0-

We know torque on a dipole is τ=P×EWhen the dipole is displaced by θ,τ=PEsinθThe electric field tries to align the dipole in the same direction as that of the field.

We know torque on a dipole is $τ = P \times E$
When the dipole is displaced by $θ, τ = P E s i n θ$
The electric field tries to align the dipole in the same direction as that of the field.