A circular coil of radius 5.0 cm and resistance 0.20 Ω is placed in a uniform magnetic field perpendicular to the plane of the coil.The magnitude of the field changes with time according to B = 0.50e^-20^t T.What is the magnitude of the current induced in the coil at the time t = 2.0 s? A)1.3 mA B)9.2 mA C)7.5 mA D)4.2 mA E)2.6 mA

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Quizplus · Accepted Answer

The induced emf (ε) is given by Faraday's law: ε = -dΦ/dt, where Φ = B * A. The area A = π * (0.05 m)^2. The rate of change of B is dB/dt = -10e^-20t. At t = 2 s, dB/dt = -10e^-40. The induced emf is ε = A * dB/dt. The current I = ε/R = (A * dB/dt) / 0.20 Ω, which calculates to approximately 2.6 mA.

A Circular Coil of Radius 5