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. - Physics

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Numerical

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. Calculate the magnitude of the torque acting on the dipole.

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Solution

Electric dipole moment, p = 4 × 10−9 C m

Angle made by p with a uniform electric field, θ = 30°

Electric field, E = 5 × 104 N C−1

Torque acting on the dipole is given by the relation,

τ = pE sinθ

= `4 xx 10^-9 xx 5 xx 10^4 xx sin30`

= `20 xx 10^-5 xx 1/2`

= `10^-4  "N m"`

Therefore, the magnitude of the torque acting on the dipole is 10−4 N m.

Concept: Electric Dipole
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Chapter 1: Electric Charges and Fields - Exercise [Page 46]

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NCERT Physics Class 12
Chapter 1 Electric Charges and Fields
Exercise | Q 1.10 | Page 46
NCERT Physics Class 12
Chapter 1 Electric Charge and Fields
Exercise | Q 10 | Page 46

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