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…

Question

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

MARKS Content Team · Accepted Answer

Correct answer: (A) 9π^2 mA. Magnetic field due to a solenoid is given by, B=μ_0ni. Therefore, flux through the coil will be, ϕ=BA=μ_0niNπr^2. According to Faraday's law of electromagnetic induction ε=(∆ϕ)/(∆t). Therefore, i=(∆ϕ)/(R∆t)=(μ_0nNπr^2)/R×(∆i)/(∆t)=(4π×10^(-7)×200×100×π×0.03^2)/4×2/0.04⇒i=9π^2 mA

A circular coil has $100$ turns, radius $3 cm$ and resistance $4 Ω$ . 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

Solution

Relevant Questions