Materials And Components MCQ Questions & Answers | ECE

Which one of the following is a ceramic insulator?

Consider the following statements:
$${\text{E}}_{\text{f}}^{\text{n}}$$ and $${\text{E}}_{\text{f}}^{\text{p}}$$ are the energies of the Fermi levels on the n and p sides of p-n junction diodes, respectively. They will vary with applied as follows:
1. $${\text{E}}_{\text{f}}^{\text{n}}$$ = $${\text{E}}_{\text{f}}^{\text{p}}$$ with bias applied.
2. $${\text{E}}_{\text{f}}^{\text{n}}$$ increase and $${\text{E}}_{\text{f}}^{\text{p}}$$ decrease with forward bias.
3. $${\text{E}}_{\text{f}}^{\text{n}}$$ decrease and $${\text{E}}_{\text{f}}^{\text{p}}$$ increase with forward bias.
4. $${\text{E}}_{\text{f}}^{\text{n}}$$ increase and $${\text{E}}_{\text{f}}^{\text{p}}$$ decreases with reverse bias.
5. $${\text{E}}_{\text{f}}^{\text{n}}$$ increase and $${\text{E}}_{\text{f}}^{\text{p}}$$ decrease with reverse bias.
Select the correct answer using the options given below:

Materials, whose specific resistance abruptly falls at very low temperature, are called

Magnetostriction is a phenomenon of

A heterojunction is formed between

Consider the following statements about semiconductors?
1. The forbidden energy gap in semiconductors lies between the valence band and conduction band.
2. The forbidden energy gap in germanium at 0 K is about 0.71 eV.
3. Semiconductors have negative temperature coefficient of resistivity.
Which of the statements given above are correct?

Consider the following statements:
In the case of a superconductor
1. the magnetic flux density is zero
2. the relative permeability is high
3. diamagnetism is large
4. transition temperature varies with isotopic mass
Of these statements

Some ceramic superconductors become superconducting

Consider the following statements:
1. Type-I superconductors undergo abrupt transition to the normal state above a critical magnetic field.
2. Type-II superconductors are highly technologically useful super-conductors because the incidence of a second critical field in them is useful in the preparation of high field electromagnets.
Which of the above statements is/are correct?

Which of the following exhibit electric hysteresis?