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AP EAMCET · PHYSICS · Electromagnetic Induction

A circular coil has 100 turns, radius 3 cm and resistance 4Ω. This coil is co-axial with a solenoid of 200 turns/cm and diameter 4 cm. If the solenoid current is decreased from 2 A to zero in 0.04 s, then the current induced in the coil is

  1. A 9π2 mA
  2. B 8π mA
  3. C 30.3 mA
  4. D 45.5 mA
Verified Solution

Answer & Solution

Correct Answer

(A) 9π2 mA

Step-by-step Solution

Detailed explanation

Magnetic field due to a solenoid is given by, B=μ0ni. Therefore, flux through the coil will be, ϕ=BA=μ0niNπr2. According to Faraday's law of electromagnetic induction ε=∆ϕ∆t. Therefore,…