Magnetostriction Effect When a ferromagnetic material in the form of rod is subjected to an alternating magnetic field parallel to its length shown in figure, the rod undergoes alternate constructions and expansion at a frequency equal to the frequency of the applied magnetic field. This phenomenon is known as magnetostriction effect . Magnetostriction Effect Due to resonance the rod is thrown into longitudinal vibrations, thereby producing ultrasonic waves in the surrounding medium. Such ferromagnetic materials which are used for the production of ultrasonic waves are called ' Magnetostriction materials '. Construction The circuit diagram is shown in figure. Circuit Diagram The ferromagnetic rod AB is clamped at the middle X. The coils L1 and L2 are wound at the ends of the rod. To the coil L1 a variable capacitor C1 is connected in parallel and this combination forms the resonator or tank circuit. One side of the resonator circuit is connec...