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A long solenoid with 15 turns per cm has a small loop of area 2.0 cm^(2) placed inside the solenoid normal to its axis. If the current carried by the solenoid changes steadily from 2.0 A to 4.0 A in 0.1 s, what is the induced emf in the loop while the current is changing ? |
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Answer» Solution :Here number of turns per unit length N = 15 turns/cm = 15 x 100 turns/m = 1,500 turns/m, area of loop `A = 2.0 cm^(2) = 2 x 10^(-4)m^(2), I_(1) = 2.0 A, I_(2) = 4.0 A and t = 0.1 s` `therefore "Induced EMF" |VAREPSILON|=(phi_(2)-phi_(1))/t=(B_(2)A-B_(1)A)/t=(B_(2)-B_(1))A/t=(mu_(0)n(I_(2)-I_(1))A)/t` `(4pixx10^(-7)xx1,500xx(4.0-2.0)xx2xx10^(-4))/0.1=7.5xx 10^(-6)V or 7.5muV` |
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