Question

Difficulty: EasyElectromagnetic Induction

A coil consisting of 5050 turns is placed in a region of changing magnetic field. If the magnetic flux passing through the coil increases uniformly from 0.2 Wb0.2\text{ Wb} to 0.6 Wb0.6\text{ Wb} in 2.0 s2.0\text{ s}, what is the magnitude of the induced electromotive force in the coil in volts?

Answer: 10 V

Answer

The magnitude of the induced electromotive force in the coil is 10 V10\text{ V}.
According to Faraday's law of electromagnetic induction, the magnitude of the induced electromotive force EE is proportional to the number of turns NN and the rate of change of magnetic flux ΔΦΔt\frac{\Delta \Phi}{\Delta t}. Given N=50N = 50, ΔΦ=0.6 Wb0.2 Wb=0.4 Wb\Delta \Phi = 0.6\text{ Wb} - 0.2\text{ Wb} = 0.4\text{ Wb}, and Δt=2.0 s\Delta t = 2.0\text{ s}, substituting these into E=NΔΦΔtE = N \frac{\Delta \Phi}{\Delta t} gives E=50×0.42.0=10 VE = 50 \times \frac{0.4}{2.0} = 10\text{ V}.

Step-by-Step Solution

1
Determine the change in magnetic flux through the coil
ΔΦ=0.6 Wb0.2 Wb=0.4 Wb\Delta \Phi = 0.6\text{ Wb} - 0.2\text{ Wb} = 0.4\text{ Wb}
Induction depends on the change in magnetic flux over time.
2
Apply Faraday's law of electromagnetic induction to solve for the induced e.m.f.
E=NΔΦΔt=50×0.4 Wb2.0 s=10 VE = N \frac{\Delta \Phi}{\Delta t} = 50 \times \frac{0.4\text{ Wb}}{2.0\text{ s}} = 10\text{ V}
Faraday's law states that the induced e.m.f. is equal to the product of the number of turns and the rate of change of flux.

Key Concept

Faraday's Law of Electromagnetic Induction
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