Reference no: EM131699150
1. Electrical conductivity of insulators is the range _____________.
(a) 10-10(?-mm)-1 (b) 10-10(?-cm)-1 (c) 10-10(?-m)-1 (d) 10-8(?-m)-1
2. Units for electric field strength
(a) A/cm2 (b) mho/meter (c) cm2/V.s (d) V/cm
3. Energy band gap size for semiconductors is in the range ________ eV.
(a)1-2 (b) 2-3 (c) 3-4 (d) > 4
4. Energy band gap size for insulators is in the range ________ eV.
(a)1-2 (b) 2-3 (c) 3-4 (d) > 4
5. Flow of electrons is affected by the following
(a) Thermal vibrations (b) Impurity atoms (c) Crystal defects (d) all
6. Not a super conductive metallic element
(a) Fe (b) Al (c) Ti (d) W
7. Fermi energy level for intrinsic semiconductors lies
(a) At middle of the band gap (b) Close to conduction band
(c) Close to valence band (d) None
8. Fermi energy level for p-type extrinsic semiconductors lies
(a) At middle of the band gap (b) Close to conduction band
(c) Close to valence band (d) None
9. Fermi energy level for n-type extrinsic semiconductors lies
(a) At middle of the band gap (b) Close to conduction band
(c) Close to valence band (d) None
10. Not an example for intrinsic semiconductor
(a) Si (b) Al (c) Ge (d) Sn
11. In intrinsic semiconductors, number of electrons __________ number of holes.
(a) Equal (b) Greater than (c) Less than (d) Can not define
12. In n-type semiconductors, number of holes __________ number of electrons.
(a) Equal (b) Greater than (c) Less than (d) Can not define
13. In p-type semiconductors, number of holes __________ number of electrons.
(a) Equal (b) Greater than (c) Less than (d) Twice
14. Mobility of holes is ___________ mobility of electrons in intrinsic semiconductors.
(a) Equal (b) Greater than (c) Less than (d) Can not define
15. Fermi level for extrinsic semiconductor depends on
(a) Donor element (b) Impurity concentration (c) Temperature (d) All
16. Value of dielectric constant for a material __________.
(a) Equal to 1 (b) Greater than 1 (c) Less than 1 (d) Zero.
17. High dielectric constant material is must for __________.
(a) Insulation of wires (b) Generators (c) Switch bases (d) Generators.
18. Dielectric constant for most polymers lies in the range of _______.
(a) 1-3 (b) 2-5 (c) 4-7 (d) 6-10.
19. Example for piezo-electric material
(a) Rochelle salt (b) Lead zirconate (c) Potassium niobate (d) Barium Titanium oxide
20. Example for ferro-electric material
(a) Potassium niobate (b) Lead titanate (c) Lead zirconate (d) quartz