Four point charges −q,+q,+q and −q are placed on y-axis at y=−2d,y=−d, and y=+2d, respectively. The magnitude of the electric field E at a point on the x-axis at x=D, with D≫d, will behave as:
Held on 9 Apr 2019 · Verified 6 Jul 2026.
E∝D41
E∝D1
E∝D31
E∝D21
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A short bar magnet placed with its axis at $30^{\circ}$ with an external field of 800 Gauss, experiences a torque of $0.016 \mathrm{~N}. \mathrm{m}$. The work done in moving it from most stable to most unstable position is $\alpha \times 10^{-3} \mathrm{~J}$. The value of $\alpha$ is $\_\_\_\_$.
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