Question

There exists a non-uniform electric field along x-axis as shown in the figure below. The field increases at a uniform rate along +ve x-axis. A dipole is placed inside the field as shown.Which one of the following is correct for the dipole?

• A. Dipole moves along positive x-axis and undergoes a clockwise rotation
• B. Dipole moves along negative x-axis and undergoes a clockwise rotation
• C. Dipole moves along positive x-axis and undergoes a anticlockwise rotation
• D. Dipole moves along negative x-axis and undergoes a anticlockwise rotation

Answer 1

The correct option is D Dipole moves along negative x-axis and undergoes a anticlockwise rotation

The dipole is placed in a non-uniform field, therefore a force as well as a couple acts on it. The force on the negative charge is more $(F\propto E)$ and is directed along negative x-axis. Thus the dipole moves along negative x-axis and rotates in an anticlockwise direction.