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 × 104N C−1. Calculate the magnitude of the torque acting on the dipole.
Electric dipole moment, p = 4 × 10−9 C m (Given)
Angle made by p with a uniform electric field, θ = 30° (Given)
Electric field, E = 5 × 104 N C−1 (Given)
Torque acting on the dipole is given by the relation,
τ = pE sinθ
= 4 × 10-9 × 5 × 104 × sin 30
= 20 × 10-5 × 
= 10-4 Nm
Therefore, the magnitude of the torque acting on the dipole is 10−4 N m.
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10 Comment(s) on this Question
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An electric dipole held at an angle of 300 with respect to a Uniform electric field of 4 x 104 N/C experiences a torque of 1.6 x10-25 Nm calculate its dipole Moment
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