An electric dipole is placed at an angle of 30° with an electric field of intensity 2x105 NC-1. It experiences a torque equal to 4 Nm. Calculate the magnitude of charge on the dipole, if the dipole length is 2cm.
An electric dipole is placed at an angle of 30° with an electric field of intensity 2x105 NC-1. It experiences a torque equal to 4 Nm. Calculate the magnitude of charge on the dipole, if the dipole length is 2cm.
2mC
8mC
6mC
4mC
The Correct Option is A
Solution and Explanation
The correct option is (C): 2mC
Here \(\theta =30^{\circ}\), \(E=2\times10^{5}NC^{-1}\)
\(\tau = 4\,Nm\),\(l=2cm=0.02m.\)
\(\tau=pEsin\theta=(ql)E\,sin\theta\)
\(\therefore \,\,q=\frac{\tau}{El\,sin\theta}=\frac{4}{2\times 10^5\times 0.02\times\frac{1}{2}}\)
\(\therefore \frac{4}{2\times10^3}=2\times10^{-3}C=2mC\)
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Concepts Used:
Electric Dipole
An electric dipole is a pair of equal and opposite point charges -q and q, separated by a distance of 2a. The direction from q to -q is said to be the direction in space.
p=q×2a
where,
p denotes the electric dipole moment, pointing from the negative charge to the positive charge.
Force Applied on Electric Dipole
