Question

An AC generated consists of a coil of $50$ turns and an area of $2.5{m^2}$rotating at an angular speed of $60\,rad/s$in a uniform magnetic field of $B = 0.37T$ between two fixed pole pieces. The resistance of the circuit including that of the coils is $500\Omega $ .
i. What is the maximum current drawn from the generator?
ii. What is flux through the coil when the current is zero.
iii. What is the flux when current is maximum.

Answer 1

Hint: A system that generates a potential difference is an alternating current (ac) generator. A simple ac generator is made up of a wire coil spinning in a magnetic field. An alternator is a type of AC generator used in automobiles to keep the battery charged and the electrical system running while the engine is running.

Complete step-by-step solution:
Given,
Angular frequency of coil $\omega $=$60\,rad/\operatorname{s} $
Uniform magnetic field $B = 0.37T$
Resistance= $500\Omega $
Number of turns=$50$
i. The maximum current drawn from the generator
${I_0} = \dfrac{{{e_0}}}{R}$ [${e_0} = emf = NBA\omega $]
${I_0} = \dfrac{{NBA\omega }}{R}$
${I_0} = \dfrac{{50 \times 2.5 \times 0.3 \times 60}}{{500}} = 4.5A$
$\therefore $ The maximum current drawn from the generator is $4.5A$
ii. Magnetic flux through the coil is greatest when current is zero.
iii. The coil, on the other side, is horizontal when the current is at its highest. The flux associated with the coil is extremely low.

Note: In electromagnetism, Lenz's law is a crucial principle. It states that when a voltage is generated by a change in magnetic flux, the induced voltage must generate a current with a magnetic field that opposes the change that generate