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Physics · PYQ NEET UG 2023
हिन्दीAn electric dipole is placed at an angle of \( 30^\circ \) with an electric field of intensity \( 2 \times 10^5\text{ N C}^{-1} \). It experiences a torque equal to \( 4\text{ N m} \). Calculate the magnitude of charge on the dipole, if the dipole length is \( 2\text{ cm} \).
Correct answer · Option 4
4 mC
Explanation
Torque \( \tau = pE \sin\theta = (q \cdot 2l) E \sin\theta \). Given \( \tau = 4 \), \( E = 2 \times 10^5 \), \( 2l = 0.02\text{ m} \), \( \theta = 30^\circ \). Thus \( 4 = q \times 0.02 \times 2 \times 10^5 \times \frac{1}{2} \), yielding \( q = 4\text{ mC} \).
