Materials And Components MCQ Questions & Answers

21.
In van der walls crystals, there exists a high degree of stability of the outer electron shell.

A. True

B. False

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22.
On the basis of the type of chemical bonds, solids may be classified into

A. Ionic crystals

B. Ionic and valence crystals

C. Ionic crystal, valence crystals and metals

D. Ionic crystals, valence crystals, metal and vander wall crystals

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23.
Which of the following are true for relative dielectric constant?
1. It is dimensionless.
2. It is equal to 1 for vacuum.
3. It is equal to 1 for all substances.

A. 1 and 2 only

B. 2 and 3 only

C. 1 and 3 only

D. 1, 2 and 3

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24.
In an intrinsic semiconductor, at a given temperature T

A. The number of electrons-hole pairs generated per second due to thermal motion are equal to the number of electron-hole pairs lost per second due to recombination

B. The number of electron-hole pairs generated per second due to thermal motion is always less than the number of electron-hole pairs lost per second due to recombination

C. The number of electron hole pairs generated per second due to thermal motion is always more than the number of electron-hole pairs lost per second due to recombination

D. Any of the above

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25.
The resistance of a photoconductor

A. Increases with increase in light intensity

B. Decreases with increase in light intensity

C. May increase or decrease with increase in light intensity

D. Remains constant

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26.
Electrical contact materials used in switches, brushes, relay must possess

A. High thermal conductivity and high melting point

B. Low thermal conductivity and low melting pointL

C. High thermal conductivity and low melting point

D. Low thermal conductivity and high melting point

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27.
The merger of hole and free electron is called

A. Covalent bonding

B. Recombination

C. Thermal energy

D. Free electrons

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28.
Ferrimagnetic materials have anti parallel orientation of equal moments of permanent dipoles.

A. True

B. False

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29.
In a metal, the valence electrons

A. Are not shared

B. Are shared only between neighbouring atoms

C. Are shared by all atoms

D. Either B or C

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30.
Wood is a diamagnetic material.

A. True

B. False

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Materials And Components MCQ Questions & Answers | ECE

21. In van der walls crystals, there exists a high degree of stability of the outer electron shell.

Answer & Solution

22. On the basis of the type of chemical bonds, solids may be classified into

Answer & Solution

23. Which of the following are true for relative dielectric constant?1. It is dimensionless.2. It is equal to 1 for vacuum.3. It is equal to 1 for all substances.

Answer & Solution

24. In an intrinsic semiconductor, at a given temperature T

Answer & Solution

25. The resistance of a photoconductor

Answer & Solution

26. Electrical contact materials used in switches, brushes, relay must possess

Answer & Solution

27. The merger of hole and free electron is called

Answer & Solution

28. Ferrimagnetic materials have anti parallel orientation of equal moments of permanent dipoles.

Answer & Solution

29. In a metal, the valence electrons

Answer & Solution

30. Wood is a diamagnetic material.

Answer & Solution

21.
In van der walls crystals, there exists a high degree of stability of the outer electron shell.

22.
On the basis of the type of chemical bonds, solids may be classified into

23.
Which of the following are true for relative dielectric constant?
1. It is dimensionless.
2. It is equal to 1 for vacuum.
3. It is equal to 1 for all substances.

24.
In an intrinsic semiconductor, at a given temperature T

25.
The resistance of a photoconductor

26.
Electrical contact materials used in switches, brushes, relay must possess

27.
The merger of hole and free electron is called

28.
Ferrimagnetic materials have anti parallel orientation of equal moments of permanent dipoles.

29.
In a metal, the valence electrons

30.
Wood is a diamagnetic material.