Materials & Compounds Electronics Engineering ECE MCQ Questions Answers
1)The magnetic moment in units of Bohr magnetron of a ferrous ion in any ferrite is
a) zero
b) 2
c) 4
d) 6
2) Recombination of electrons and holes takes place when :
(a) an electron falls into a hole
(b) a positive ion and a negative ion bond together
(c) avalanche electron becomes a conduction electron
(d) an atom is formed
3)The magnetization ‘M’ of a superconductor in a field of H is
a) extremely small
b) – H
c) – 1
d) zero
4) A semiconductor has generally ……………… valence electrons.
a) 2
b) 3
c) 6
d) 4
5) The difference between the number of atoms in a unit cell of a bcc crystal and an fcc crystal is
a) 1
b) 2
c) 4
d) 6
6) For an insulating material, dielectric strength and dielectric loss should be respectively
a) high and high
b) low and high
c) high and low
d) low and low
7) When a pure semiconductor is heated, its resistance …………..
a) Goes up
b) Goes down
c) Remains the same
d) Can’t say
8) When BCC iron is heated, is changes to FCC iron resulting in
a) con traction in volume
b) increase in volume
c) no change in volume
d) crack in the material
9) Fermions are the particles, which obey
a) Maxwell-Boltzmann’s statistics
b) Bose-Einstein’s statistics
c) Heisenberg’s uncertainty principle
d) pauli’s exclusion principle
10) Which of the following materials are piezoelectric?
a) Mica and quartz
b) Mica, barium titanate and quartz
c) Mica and diamond
d) Barium titanate and quartz