ENGINEERING MATERIALS IN EE QUIZ

Materials which lack permanent magnetic dipoles are called

semi-magnetic.

None of these

ferro-magnectic.

dia-magnetic.

TRUE ANSWER : ?
YOUR ANSWER : ?

Almost the entire mass of an atom is concentrated in the

electrons.

neutrons.

nucleus.

protons.

TRUE ANSWER : ?
YOUR ANSWER : ?

Absolute permittivity of a dielectric medium is represented by

εoεr.

εo / εr.

None of these

εr / εo.

TRUE ANSWER : ?
YOUR ANSWER : ?

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

none of above.

5.

8.

51.

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following gives materials in order of decreasing values of permeability?

Cobalt, nickel, aluminium, iron.

Pure iron, silicon iron, aluminium, bismuth.

Silver, copper, aluminium, iron.

Permalloy, nickel, air, water.

TRUE ANSWER : ?
YOUR ANSWER : ?

The core of a transformer for microwave frequency should be made of

ferrites.

iron.

silicon.

silicon carbide.

TRUE ANSWER : ?
YOUR ANSWER : ?

Magnetic recording tape is most commonly made from

iron-dust.

ferric-oxide.

small particles of iron.

silicon-iron.

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following is the least desired property in magnetic materials for electrical engineering applications ?

Large hysteresis loop.

High electrical resistivity.

High magnetic permeability.

All of these

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following is the example for piezo-electric material ?

None of these

Copper

Lead zirconate titanate

Potassium niobate

TRUE ANSWER : ?
YOUR ANSWER : ?

In Bohr’s model of atomic structure, the nucleus consists of

protons.

electrons.

protons and neutrons.

electrons and protons.

TRUE ANSWER : ?
YOUR ANSWER : ?

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