A circular coil of one turn of radius 5.0cm is rotated about a diameter with a constant angular speed of 80 revolutions per minute.
A circular coil of one turn of radius 5.0cm is rotated about a diameter with a constant angular speed of 80 revolutions per minute. A uniform magnetic field B = 0.010T exists in a direction perpendicular to the axis of rotation. Find (a) the maximum emf induced, (b) the average emf induced in the coil over a long period and (c) the average of the squares of emf induced over a long period.
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emf = dϕ/dt = dB.Acosθ/dt
= BAsinθω = –BAωsinθ
(dq/dt = the rate of change of angle between arc vector and B = ω)
(a) emf maximum = BAω = 0.010 × 25 × 10–4 × 80 x (2π x π)/6
= 0.66 × 10–3 = 6.66 × 10–4volt.
(b) Since the induced emf changes its direction every time,
so for the average emf = 0
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