Question

A dipole is placed in an electric field as shown. In which direction will it move

• A. towards the right as its potential energy will increase.
• B. towards the left as its potential energy will increase
• C. towards the right as its potential energy will decrease
• D. towards the left as its potential energy will decrease

Answer 1

The Correct Option is C

To determine the direction in which the dipole will move, we need to understand the interaction between a dipole and an electric field.

A dipole consists of two equal and opposite charges separated by a distance. When placed in a uniform electric field \(\vec{E}\), the dipole experiences a torque but not a net force. However, in a non-uniform electric field, the dipole experiences a net force that moves it from higher potential energy to lower potential energy.

The potential energy \(U\) of a dipole in an electric field is given by:

\(U = -\vec{p} \cdot \vec{E}\)

where \(\vec{p}\) is the dipole moment vector. The dipole will move in a direction that decreases its potential energy.

Given the options and the correct answer, the dipole moves:

• Towards the right as its potential energy will decrease.

Thus, in a non-uniform electric field as depicted, the dipole moves towards the region of the strongest field (right), decreasing its potential energy.

In summary, in a non-uniform field, a dipole experiences a force in the direction of increasing electric field gradient. Therefore, it will move towards the right where its potential energy decreases.