Question

Which of the following materials is used for the generation of ultrasonic waves by using magnetostriction effect?
1. Parmagnetic material
2. Ferromagnetic material
3. Diamagnetic materials
4. Both paramagnetic and diamagnetic material

Answer 1

Correct Answer - Option 2 : Ferromagnetic material

Ferromagnetic substance or material is used for the generation of ultrasonic waves by using the magnetostriction effect.

Magnetostriction Effect:

• When a magnetic field is applied parallel to the length of a ferromagnetic rod made of a material such as iron or nickel, a small elongation or contraction occurs in its length. This is known as magnetostriction.
• The change in length depends on the intensity of the applied magnetic field and the nature of the ferromagnetic material.
• The change in length is independent of the direction of the field.

• Magnetostriction is a property of ferromagnetic materials that causes them to change their shape when subjected to a magnetic field.
• The effect was first identified in 1842 by James Joule when observing a sample of nickel.
• This effect can cause losses due to frictional heating in susceptible ferromagnetic cores.