Question

One hundred turns of insulated copper wire are wrapped around a wooden cylindrical core of cross-sectional area 1.30×10-3 m2. The two terminals are connected to a resistor. The total resistance in the circuit is 15.0 O.
If an externally applied uniform longitudinal magnetic field in the core changes from 1.60 T in one direction to 1.60 T in the opposite direction, how much charge flows through the circuit (in Coulombs)?

Answer 1

Data given, Number of turns of copper wire is N-100 A-1.3x103m2 R 15Ω Cross-sectional area o f core is Total resistance in the circuit is Calculate change in magnetic field dB 1.6-(-1.6) 3.2T Use Faraday's law of electromagnetic induction, emf induced due to change in magnetic field in small time interval dt is given by db dt Consider Ohm's law, current I flowing in the circuit is V- IR dt

Here, da is the small amount of charge flowing through the circuit in time dt. Equate equation (1) and (2). Rearange for charge flows through the coil. NA(dB) dq- Substitute the known values. 100x1.3 x10 x3.2 15 0.02773C Hence, charge flows through the coil is 0.02773 C