Define the construction of ultrasonic magnetostriction method.

Construction:

The ends of the ferromagnetic rod A and B are wound through the coils L₁and L as given in figure below. The coil L is attached to the collector of the transistor and the coil L₁is attached to the base of the transistor as demonstrated in the figure. There frequency of the oscillatory circuit (LC) can be adjusted through the condenser C and the current can be noted with the milli-ammeter that connected across the coil L. The battery linked between emitter and collector provides needed biasing that is, emitter is forward biased and collector is reverse biased for the NPN transistor. Therefore, current can be produced through applying essential biasing to the transistor with the assist of the battery.