Target Exam

CUET

Subject

Physics

Chapter

Electric Charges and Fields

Question:

Choose the correct statements:

A. In uniform electricfield E, the net force on electric dipole is zero.
B. The torque on dipole in electric field is $τ= PE\cos θ$, where θ is angle between $\vec P$ and $\vec E$
C. In non uniform Electric field, when dipole moment P is parallel to E, the dipole has a net force in the direction of decreasing field.
D. The direction of torque is perpendicular to both $\vec P$ and $\vec E$.
E. The net torque is zero if E is not uniform.

Choose the correct answer from the options given below:

Options:

A and D only

C, D and E only

D and E only

A, D and E only

Correct Answer:

A and D only

Explanation:

The correct answer is Option (1) → A and D only

(A) True, In a uniform electric field, the forces on the positive and negative charges of the dipole are equal and opposite.

(D) True, the torque on electric dipole in electric field is given by $\vec τ=\vec p×\vec E$. Hence, the torque is perpendicular to both $\vec p$ and $\vec E$.