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Force and torque experienced by an electric dipole in a uniform electric field |
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Answer» HEYA..... _____________________________________________________________ QUESTION:- force &torque experienced by an electric dipole in a uniform electric field? ANSWER: Consider an electric dipole placed in a uniform electric field of strength E such that it's dipole moment p makes an angle theata with the direction of E Let 2l be the length of the dipole With +Q and -q charges The force on the charges is F+−→ = +qE→ F−−→ = −qE→ The components of force perpendicular to the dipole are: F⊥+ = +qE sinθ F⊥− = −qE sinθ Since the force magnitudes are equal and are separated by a distance d, the torque on the dipole is GIVEN by: Torque (τ) = Force × distance seperating forces τ = d qE sin θ Since dipole moment is given by p = qd And the direction of the dipole moment is from the positive to the negative charge; it can seen from the above equation that the torque is the cross product of the dipole moment and electric field. Notice that the torque is in the clockwise direction (hence negative) in the above figure if the direction of Electric field is positive. Thus, τ = −pE sin θ Or, τ→ = p→ × E→ |τ→| = |p→ × E→| = pE sin θ _____________________________________________________________ Hope it helps ============= |
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