Semiconductor Materials » Exercise – 1
28. Which of the following statements are correct ?
1. In semiconductor, the mobility of electrons is more than that of holes.
2. In semiconductor, when temperature increases, the resistivity also increases.
3. Metal has positive TCR.
4. In metals, thermal conductivity is inversely proportional to electrical conductivity at constant temperature.
(a) 1, 2, 3
(b) 1, 2, 4
(c) 2, 3, 4
(d) 1, 3, 4Subject Name : Electronics Engineering Exam Name : IIT GATE, UPSC ESE, RRB, SSC, DMRC, NMRC, BSNL, DRDO, ISRO, BARC, NIELIT Posts Name : Assistant Engineer, Management Trainee, Junior Engineer, Technical Assistant Electronics & Communication Engineering Books
GATE 2023 Total Info ENGG DIPLOMA UGC NET Total Info IES 2023 Total Info PSUs 2022 Total Info CSIR UGC NET Total Info JAM 2023 Total Info M TECH 2023 Total Info RAILWAY 2022 Total Info
Related Posts
Semiconductor Materials » Exercise - 4 151. The addition of a very small quantity of aluminium to a silicon or germanium crystal makes it : (a) A good conductor (b) A good insulator (c) P-type semiconductor (d) N-type semiconductor 152. An intrinsic semiconductor at the absolute zero of temperature : (a) Behaves like a semiconductor (b) Behaves like an insulator (c) Has a few free electrons and same number of holes (d) Has a large number of holes and a few electrons 153. In a substance the conduction band and valence band are separated by a energy gap of the order of 1 eV, and there are at room temperature as money electrons in the conduction band as holes in the valence band. The substance is : (a) An intrinsic semiconductor (b) A p-type semiconductor (c) A N-type semiconductor (d) A doped semiconductor 154. The majority carriers of electricity in a p-type semiconductor are : (a) Free electrons (b) Holes (c) Both electrons and holes (d) Free ions 155. N-type semiconductor is obtained when silicon or germanium is doped by : (a) Phosphorus (b) Boron (c) Aluminium (d) Gallium 156. A p-type semiconductor is : 1. A silicon crystal doped with arsenic impurity. 2. A silicon crystal…- Conducting Materials » Exercise - 110. The conductivity of an extrinsic semiconductor : (a) decreases with temperature (b) increases with temperature (c) remains constant with temperature (d) decreases and then increases with temperature
- Semiconductor Materials » Exercise - 4187. The conductivity of semiconductor : (a) Is independent of temperature (b) Varies inversely as temperature (c) Increases with increase in temperature (d) May increase or many decrease with rise in temperature
- Semiconductor Materials » Exercise - 281. Temperature coefficient of resistance of a pure semiconductor specimen is : (a) Zero (b) Positive (c) Negative (d) None of the above
- Semiconductor Materials » Exercise - 3103. The resistivity of pure silicon decreases : (a) With decrease in temperature (b) With increase in temperature (c) With constant temperature (d) None of these