In a coil of resistance 10Ω, the induced current due to changing magnetic flux is shown as a straight line from 4A at t=0 to zero at t=0.1s. What is the magnitude of change in magnetic flux through the coil? [Image]
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Question

In a coil of resistance 10Ω, the induced current due to changing magnetic flux is shown as a straight line from 4A at t=0 to zero at t=0.1s. What is the magnitude of change in magnetic flux through the coil? [Image]

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G1 Physics · Accepted Answer

Step 1: Induced current plotted in the PDF decreases linearly from 4 A at t=0 to 0 A at t=0.1 s in a coil of resistance 10Ω. Step 2: Total induced charge Q=∫I dt is the triangle area under I–t graph: Q=(1/2)(4 A)(0.1s)=0.20 C. Step 3: Since ε=IR and |ΔΦ|=∫|ε|dt=RQ, magnitude of magnetic flux change is 10×0.20=2 Wb. Answer B. Final answer: (B) 2Wb.