An electric dipole is placed in a varying electric field. The dipole then experiences:

The correct answer is option 2) i.e a torque and a net force

CONCEPT:

• Electric field strength is a measure of the electric field intensity at a point due to a charge. It is the amount of electric force produced per unit charge.
  • Electric field strength (E) at a point due to a point charge q is given by the formula

 \(E =\frac{F}{q}\)

Where r is the distance from the point charge to the point at which E is determined.

• Electric dipole a couple formed from two equal opposite charges q and –q, which are separated by a distance 2a.

EXPLANATION:

In a uniform electric field:

• When an electric dipole is placed in a uniform electric field of intensity E, the negative and positive charges experience two forces -qE and +qE respectively.
• These two forces are opposite and hence, the net force the dipole experiences will be zero. However, Since they are separated by a distance, a torque is produced. 

In a varying or non-uniform electric field:

• In a varying electric field, the force experienced by the two charges of the dipole will be of different magnitudes, and hence, the dipole will experience a net force.
• Since the charges are separated by a distance, they will experience a torque as before.

Thus, an electric dipole is placed in varying electric field experiences a torque and a net force.