ENGINEERING MATERIALS IN EE QUIZ

Which statement is not true of ferromagnetic materials.

They have large magnetic susceptibility.

They have fixed value of μr.

They lose their nonlinearly property above the Curie temperature.

Energy loss is proportional to the area of hysteresis loop.

TRUE ANSWER : ?
YOUR ANSWER : ?

A degaussing is the process of

demagnetising metallic parts.

removal of magnetic impurities.

remagnetising metallic parts.

removing gases from materials.

TRUE ANSWER : ?
YOUR ANSWER : ?

When a ferromagnetic substance is magnetized small changes in dimensions occur. Such a phenomenon is known as

magneto-calorisation.

magnetic hysteresis.

magnetic expansion.

magnetostriction.

TRUE ANSWER : ?
YOUR ANSWER : ?

Absolute permittivity of a dielectric medium is represented by

None of these

εo / εr.

εoεr.

εr / εo.

TRUE ANSWER : ?
YOUR ANSWER : ?

When will be the electron pair bonding occurs ?

Lack holes

Share holes

None of these

Share electrons

TRUE ANSWER : ?
YOUR ANSWER : ?

The intensity of magnetization, M, of a ferro magnetic solid

is independent of temperature.

decreases with increasing temperature.

depends on method of heating.

increases with increasing temperature.

TRUE ANSWER : ?
YOUR ANSWER : ?

In electrical machines the material preferred for pole shoes of electromagnets is

aluminium.

lead.

pure iron.

copper.

TRUE ANSWER : ?
YOUR ANSWER : ?

When the atomic magnetic moments are randomly oriented in a solid its magnetic behavior is termed as

poly crystalline.

semi-magnetic.

anti-ferromagnetic.

paramagnetic.

TRUE ANSWER : ?
YOUR ANSWER : ?

How many valence electrons would be found in an atom with the atomic number of 51?

none of above.

8.

5.

51.

TRUE ANSWER : ?
YOUR ANSWER : ?

Permittivity of free space is equal to

8.854 × 10 - 10 F / m.

8.854 × 10 - 12 F / m.

8.854 × 10 - 11 F / m.

8.854 × 10 - 13 F / m.

TRUE ANSWER : ?
YOUR ANSWER : ?

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