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Question
An electric dipole of dipole moment 2 × 10-8 C-m in a uniform electric field experiences a maximum torque of 6 × 10-4 N-m. The magnitude of the electric field is ______.
Options
2.2 × 103 Vm-1
1.2 × 104 Vm-1
3.0 × 104 Vm-1
4.2 × 103 Vm-1
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Solution
An electric dipole of dipole moment 2 × 10-8 C-m in a uniform electric field experiences a maximum torque of 6 × 10-4 N-m. The magnitude of the electric field is 3.0 × 104 Vm-1.
Explanation:
Given: Electric dipole moment,
`p = 2 xx 10^-8` N/C
Maximum torque, `tau = 6 xx 10^-4` N-m
θ = 90°
Electric field, E = ?
The torque acting on the dipole:
τ = pE sinθ
⇒ `6 xx 10^-4 = 2 xx 10^-8 xx E`
⇒ E = `3 xx 10^4` Vm-1
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