A conducting circular loop is placed in a uniform magnetic field 0.04 T with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at 2 mm/s. The induced emf in the loop when the radius is 2 cm is:

Question

Dr. Abubacker · Accepted Answer

[Solution from source] Emf = B dA/dt = B × 2πr × dr/dt = 0.04 × 2π × 0.02 × 2 × 10⁻³ = 3.2π × 10⁻⁶ V = 3.2π μV. Missing the factor 2 from d(πr²)/dt gives 1.6π μV. Answer (4).

Q. A conducting circular loop is placed in a uniform magnetic field 0.04 T with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at 2 mm/s. The induced emf in the loop when the radius is 2 cm is:

Explanation

Reviewed by Dr. Abubacker

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