Question 4. A dipole is placed in an electric field as shown. In which direction will it move?
(1) towards the left as its potential energy will increase.
(2) towards the right as its potential energy will decrease.
(3) towards the left as its potential energy will decrease.
(4) towards the right as its potential energy will increase.
Answer: Option (2)
Explanation:
The given electric field is non-uniform and directed towards the right, as indicated by the arrows spreading out.
The electric dipole consists of charges +q and -q, with the dipole moment directed from -q to +q.
In a non-uniform electric field, a dipole experiences a net force in addition to a torque.
The force on the positive charge is in the direction of the electric field, while the force on the negative charge is opposite to the electric field.
Since the electric field strength is greater towards the right, the force on the positive charge +q is greater in magnitude than the force on the negative charge -q.
As a result, a net force acts on the dipole towards the right.
In a non-uniform electric field, a dipole always moves in the direction where its potential energy decreases.
Therefore, the dipole will move towards the right as its potential energy decreases.
Hence, the correct option is (2).