Always maximum flux reaches from zero to maximum in one quarter of the cycle.
That is in … of second. That is equal to 1/200 second.
Average rate of change of flux = Qm / … f.
= Qm * 4 * f. = 4 f Qm Weber / second.
As the coil has N turns the average emf induced in the coil = 4 f Qm N volts.
But the rms. Value = average value * form factor.
∴ rms. Value of emf = 1.11 * 4 f Qm N volts.
= 4.44 f Qm N volts.
