An alternator consists of a coil of area a with n turns that rotates in a uniform field b around a diameter perpendicular to the field with a rotation frequency f.
a)find the fem in the coil
b)what is the amplitude of the alternating voltage if n= 100 turns, a = 10 ^ -2 m ^ 2, b = 0.1t, f = 2000 rev/min

(a): .

(b): 20.94 Volts.

Explanation:

Given:

The magnetic flux linked with a coil is defined as

where,

Assuming that the magnetic field is along the normal to the plane of the coil, initially.

Therefore, at any later time t, the angle which the magnetic field makes with the normal to the plane of the coil is is given by

Therefore, the magnetic flux linked with the coil at any time t is given by

According to the Faraday's law of electromagnetic induction, the emf induced in the coil is given by

The amplitude of the alternating voltage is the maximum value of the induced emf in the coil, the induced emf in the coil is maximum when .

Therefore, the amplitude of the alternating voltage is given by

Given values are:

Putting all these values,

b.a device that inputs heat into a cool object