When an electric dipole is placed in a uniform electric field, the net force on the dipole will be:

CONCEPT:

Electric dipole

• When two equal and opposite charges are placed at a very small distance to each other then this arrangement is called an electric dipole. 
• The electric dipole moment is defined as the product of the magnitude of one charge and the distance between the charges in an electric dipole.

⇒ P = q × 2r    

Where 2r = distance between the two charges

EXPLANATION:

Electric dipole in a uniform external field:

• We know that when a charge q is placed in electric field E, it experiences a force F, the force is given as,

⇒ F = qE     -----(1)

• So when an electric dipole is placed in the electric field according to the diagram,
• The force on the +q charge due to electric field is given as,

⇒ F1 = qE

Similarly, the force on the -q charge due to the electric field is given as,

⇒ F2 = qE

• The force F1 and F2 will act opposite to each other.
• So the net force on the dipole will be,

⇒ F = F₁ - F₂

⇒ F = qE - qE

⇒ F = 0

• Hence, option 2 is correct.