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Grade 12th passAIPMT

A semicircular non conducting ring of radius R is uniformly charged with total charge Q. find the electrostatic force on q placed at the centre of curvature of half ring

Profile image of Vinayak
8 Years agoGrade 12th pass
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1 Answer

Profile image of Eshan
8 Years ago
Dear student,

The charge per unit length of the ring=\lambda=\dfrac{Q}{\pi R}
Electric field at the center of curvature of half ring=E=\int_{-\pi/2}^{\pi/2}\dfrac{k(\lambda Rd\theta)}{R^2}cos\theta
=\dfrac{2k\lambda }{R}=\dfrac{\lambda}{2\pi\epsilon_0 R}

Hence force on the charge kept at that point=qE=\dfrac{\lambda q}{2\pi\epsilon_0R}=\dfrac{Qq}{2\pi^2\epsilon_0 R^2}