MagnetostrictionOscillator

1.	MagnetostrictionOscillator
Answer» <p>Principle</p><p>It works under the principle of Magnetostriction effect.</p><p>When a ferromagnetic rod is kept in an alternating magnetic field the rod is set into longitudinal vibrations, this happens due to change in the length of the rod.</p><p>This longitudinal vibrations, result in the formation of ultrasonic waves at resonance.</p><p>Resonance is the condition at which the frequency of the oscillator match with the natural frequency of rod.</p><p>Working:</p><p>1) The rod is initially magnetized by the DC power supply.</p><p>2) When the battery is initially switched on the current is induced in the transistor.</p><p>3) The transistor is properly biased.</p><p>4) Emitter- forward biased, Collector- reverse biased.</p><p>5) An emf is induced in coil L1, this induces an emf to coil L2 & a part of it is feed as input to the base. Hence, this feedback system makes transistor operates continuously.</p><p>6) The varying frequency can be obtained by altering the capacitance value of condenser.</p><p>7) At resonance Ultrasonic waves will be produced.</p><p>Natural frequency of rod= Frequency of oscillator circuit</p>

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