Question

A uniformly charged ring of radius 3a and total charge q is placed in xy-plane centered at origin. A point charge q is moving towards the ring along the z-axis and has speed v at z = 4a. The minimum value of v such that it crosses the origin is:
(A) √(2/m)(1/5 . q²/4π∈₀a)¹/²
(B) √(2/m)(1/15 . q²/4π∈₀a)¹/²
(C) √(2/m)(4/15 . q²/4π∈₀a)¹/²
(D) √(2/m)(2/15 . q²/4π∈₀a)¹/²

Answer 1

Answer:

C) √(2/m)(4/15 . q²/4π∈₀a)¹/² will be the right answer

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