Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
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
PhysicsElectromagnetic InductionAP EAMCETAP EAMCET 2022 (04 Jul Shift 2)
Options:
  • A 9π2 mA
  • B 8π mA
  • C 30.3 mA
  • D 45.5 mA
Solution:
2217 Upvotes Verified Answer
The correct answer is: 9π2 mA

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=ϕt. Therefore,

i=ϕRt=μ0nNπr2R×it=4π×10-7×200×100×π×0.0324×20.04i=9π2 mA

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.