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Most Important Selected Qs for JEE AdvancedPhysicsMagnetic Effects of Current

A electron is projected normally from the surface of a sphere with speed v₀ in a uniform magnetic field perpendicular to the plane of the paper such that its strikes symmetrically opposite on the sphere with respect to the x-axis. Radius of the sphere is ' a ' and the distance of its centre from the wall is ' b '. What should be magnetic field such that the charge particle just escapes the wall

Options

  1. AB = 2 b m v₀ ( ~b ^2- a ^2 ) e
  2. BB = 2 bmv ₀ ( a ^2- b ^2 ) e
  3. CB = ( a ^2- b ^2 ) 2 bmv ₀
  4. DB = me ( b ^2- a ^2 ) 2 bmv

Correct answer

A. B = 2 b m v₀ ( ~b ^2- a ^2 ) e

Step-by-step solution

aligned & e v₀ B= m v₀^2 R & B= mv ₀ eR & a^2+R^2 =b-R & R= b^2-a^2 2 b & B= 2 b m v₀ (b^2-a^2 ) e aligned

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