An electric dipole with dipole moment 4 × 10-9 C m is aligned at 30° with the direction of a uniform electric field of magnitude 5 × 104 N C -1. The magnitude of the torque acting on the dipole is

Question

An electric dipole with dipole moment 4 × 10-9 C m is aligned at 30° with the direction of a uniform electric field of magnitude 5 × 104 N C -1. The magnitude of the torque acting on the dipole is (A) 10-3 N m (B) 10-4 N m (C) 1.7 × 10-3 N m (D) 1.7 × 10-4 N m

Tardigrade Admin · Accepted Answer

τ=p E sin θ=(4 × 10-9 Cm )(5 × 104 N C -1) sin 30° =10-4 N m

Q. An electric dipole with dipole moment $4 \times 1 0^{- 9} C m$ is aligned at $3 0^{\circ}$ with the direction of a uniform electric field of magnitude $5 \times 1 0^{4} N C^{- 1}$ . The magnitude of the torque acting on the dipole is

$1 0^{- 3} N m$

$1 0^{- 4} N m$

$1.7 \times 1 0^{- 3} N m$

$1.7 \times 1 0^{- 4} N m$

$τ = pE sin θ = (4 \times 1 0^{- 9} C m) (5 \times 1 0^{4} N C^{- 1}) sin 3 0^{\circ}$
$= 1 0^{- 4} N m$

Q. An electric dipole with dipole moment 4×10−9Cm is aligned at 30∘ with the direction of a uniform electric field of magnitude 5×104NC−1. The magnitude of the torque acting on the dipole is

10−3Nm

10−4Nm

1.7×10−3Nm

1.7×10−4Nm