Mock Test

Conductivity

by Anish
Updated On:

Conductivity

Total Questions: 26

21. The most commonly used material for making transistors is- [U.P.P.C.S. (Pre) 2015]

Correct Answer: (b) Silicon
Solution:Germanium and silicon are the main elements which are used as a semiconductor in transistors. Their conductivity on the normal/room temperature lies between the conductivity of conductors and insulators.

22. Which one of the following is an important component of a transistor? [U.P.R.O/A.R.O.(pre) 2016]

Correct Answer: (b) Germanium
Solution:Germanium and silicon are the main elements which are used as a semiconductor in transistors. Their conductivity on the normal/room temperature lies between the conductivity of conductors and insulators.

23. Which of the following are semiconductors? [U.P.P.C.S. (Mains) 2005]

1. Silicon

2. Quartz

3. Ceramics

4. Germanium

Choose the correct answer from the following alternatives:

Correct Answer: (c) 1 and 4
Solution:In solid state electronics, either pure silicon or germanium may be used as the intrinsic semiconductor which forms the starting point for fabrication. Each has four valence electrons but germanium at a given temperature has more free electrons and higher conductivity.

Silicon is by far the more widely used semiconductor for electronics because it can be used at much higher temperatures than germanium.

24. Which of the following is a semiconductor? [U.P.P.C.S. (Pre) (Re. Exam) 2015]

Correct Answer: (d) Germanium
Solution:Germanium: Germanium is a metalloid and a well-known semiconductor material. It was one of the first semiconductor materials studied and used in early electronics before silicon became dominant.

Semiconductors: Semiconductors are materials that have electrical conductivity between that of a conductor (like copper or aluminum) and an insulator (like 1 plastic or wood). Their conductivity can be controlled by factors like temperature, light, and the addition of impurities (doping).

25. Which of the following elements is a semiconductor? [U.P. P.C.S. (Pre) 2018]

Correct Answer: (b) Silicon
Solution:Silicon: Silicon is a semiconductor. It is the most widely used semiconductor material in the electronics industry, forming the basis of transistors, integrated circuits, solar cells, and many other devices.

Semiconductors: Semiconductors are materials that have an electrical conductivity between that of a conductor (like metals) and an insulator (like rubber or glass). Their conductivity can be controlled by factors like temperature, light, and the addition of impurities (doping).

26. The Government of India has totally banned the export of burnt coal (Jhama) because it contains recoverable amount of a metal/element which is used in transistors. Which one of the following is that element? [I.A.S. (Pre) 1993]

Correct Answer: (b) Germanium
Solution:Germanium, a brittle silvery white semi-metallic element is typically obtained from smelting zinc or as a by- product of burnt coal (Jhama). This element is used in transistors.

Anish

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