COMEDK · Physics · 22. Electromagnetic Induction
A conducting circular loop is placed in a uniform magnetic field \(\mathrm{B}=0.125 \mathrm{~T}\) with its plane perpendicular to the loop. If the radius of the loop is made to shrink at a constant rate of \(2 \mathrm{~mm} \mathrm{~s}^{-1}\), then the induced emf when the radius is \(4 \mathrm{~cm}\) is
- A \(\dfrac{2}{3}\mu V\)
- B \(20 \pi \mu V\)
- C \(0.52 \pi \mu V\)
- D \(\dfrac{3 \pi}{2} \mu V\)
Answer & Solution
Correct Answer
(B) \(20 \pi \mu V\)
Step-by-step Solution
Detailed explanation
The magnetic flux \(\Phi\) through the circular loop is given by \(\Phi = B A = B (\pi r^2)\), where \(B\) is the magnetic field and \(r\) is the radius of the loop. The induced electromotive force (emf) \(\varepsilon\) is given by Faraday's law of induction:…
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