InterviewSolution
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InterviewSolution
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A small electric dipole having dipole moment ` ` vec p` is placed along x-axis as shown in the figure . A semi-infinite uniformly charged di-electric thin rod is placed along `x` axis , with one end coinciding with origin . If linear charge density of rod is `+ lambda` and distance of dipole from rod is `a` then calculate the electric force acting on dipole . |
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Answer» Correct Answer - ` (- P lambda)/( 4 pi varepsilon_0 a^2)`. Field at `P` due to elemental length is `dE = (K lambdadx)/(x^2)` `E = int dE = K lambda int _a^(infty) = (K lambda)/a = 1/(4 pi in_0) (lqambda)/a` Potential energy of dipole `U =- Pe cos theta` `U = - ( p lambda) /( 4 pi in_0 a)` `F= - (dU)/(da) rArr F= ( lambda )/(4pi in_0 a^2)`. |
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