Target Exam

CUET

Subject

Physics

Chapter

Electric Charges and Fields

Question:

An electric dipole with dipole moment $3 × 10^{-9} Cm$ is aligned at 30° with the direction of uniform electric field of magnitude $6 × 10^4 NC^{-1}$. What will be the magnitude of the torque acting on the dipole?

Options:

$9×10^{-5} Nm$

$2.5 × 10^{-14} Nm$

$2×10^{13} Nm$

$1.56 × 10^{-4} Nm$

Correct Answer:

$9×10^{-5} Nm$

Explanation:

The correct answer is Option (1) → $9×10^{-5} Nm$

The torque ($τ$) acting on an electric field ($\vec E$) is,

$τ=pE\sin θ$

$=(3×10^{-9})×(6×10^4)×\sin(30°)$

$=9×10^{-5} Nm$