Positive magnetostriction exists when dipoles are repel other. both are correct. dipoles are attract each other. none of above. TRUE ANSWER : ? YOUR ANSWER : ?
Indicate which of following material does not retain magnetism permanently soft iron. stainless steel. hardness steel. none of above. TRUE ANSWER : ? YOUR ANSWER : ?
What are insulating materials that can tolerate maximum temperature? Mica. Glass. Porcelain. All of these. TRUE ANSWER : ? YOUR ANSWER : ?
Materials which lack permanent magnetic dipoles are called None of these ferro-magnectic. semi-magnetic. dia-magnetic. TRUE ANSWER : ? YOUR ANSWER : ?
ALNICO is an alloy of aluminium, nickel, iron and cobalt. aluminium, nickel. iron, aluminium. iron, cobalt, nickel. TRUE ANSWER : ? YOUR ANSWER : ?
When a ferromagnetic substance is magnetized small changes in dimensions occur. Such a phenomenon is known as magnetic expansion. magnetostriction. magneto-calorisation. magnetic hysteresis. TRUE ANSWER : ? YOUR ANSWER : ?
In ferromagnetic materials the constituent is only iron. the atomic magnetic moments are antiparallel and unequal. the atomic magnetic moments are parallel. one of the constituent is iron. TRUE ANSWER : ? YOUR ANSWER : ?
The numberof atoms per unit cell in a B.C.C structure is 7. 4. 2. 12. TRUE ANSWER : ? YOUR ANSWER : ?
Substance having permeability less than the permeability of free space, are known as diamagnetic. bipolar. paramagnetic. ferromagnetic. TRUE ANSWER : ? YOUR ANSWER : ?
It is difficult to magnetize steel because it has high permittivity. low permeability. high permeability. low susceptibility. TRUE ANSWER : ? YOUR ANSWER : ?