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99 Percentile Qs Bank for JEE MainPhysicsElectromagnetic Induction

A wire loop enclosing a semi-circle of radius R is located on the boundary of a uniform magnetic field of induction B → . At time t = 0 , the loop is set into rotation with velocity ω ? about its axis 0 , coinciding with a line of vector B → on the boundary as shown in the figure. The emf induced in the loop is

Options

  1. AB R 2 2 ω
  2. BB R ω
  3. CB R 2 ω
  4. DB R 2 2 ω

Correct answer

A. B R 2 2 ω

Step-by-step solution

d ϕ = B → · d s → = B d s = B 1 2 ϕ R 2 ( ϕ = Sector angle) Magnitude of induced emf = - d ϕ d t = B 1 2 R 2 d ϕ d t = B R 2 ω 2

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