Materials And Components MCQ Questions & Answers

51

Consider the following statements with regard to FCC structure:
1. Number of nearest neighbour atoms is twelve.
2. Packing efficiency is 0.74.
3. There is an atom at the body centre of the unit cell.
Which of the statements given above is/are correct?

A) 1, 2 and 3 B) 1 and 2 C) 2 and 3 D) 1 and 3

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Answer & Solution

Answer: Option B

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52

Pure Metals generally have

A) High Conductivity & Low temperature coefficient B) High Conductivity & High temperature coefficient C) Low Conductivity & zero temperature coefficient D) Low Conductivity & High temperature coefficient

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Answer & Solution

Answer: Option B

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53

Electrical conductivity, thermal conductivity and magnetic properties of ceramic material are

A) very high all the time B) very low all the time C) dependent on the material D) ascertainable, instance to instance

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Answer & Solution

Answer: Option C

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54

Forbidden gap in a semiconductor is

A) large B) very large C) small D) not present

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Answer & Solution

Answer: Option C

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55

Which one of the following does not come under the category of ceramic material?

A) Al₂O₃ B) SiO₂ C) Si₂N₄ D) siC

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Answer & Solution

Answer: Option C

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56

Polyethylene is produced by

A) condensation polymerization B) addition polymerization C) co-polymerization D) all of the above

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Answer & Solution

Answer: Option B

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57

What are the materials which exhibit electric polarization even in the absence of an applied electric field called?

A) Ferromagnetic B) Paramagnetic C) Ferroelectric D) Anti-ferroelectric

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Answer & Solution

Answer: Option C

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58

The structure sensitive property of a superconductor is

A) Critical magnetic field B) Transition temperature C) Critical current density D) None of the above

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Answer & Solution

Answer: Option C

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59

A hetero-structure laser is better than a diode laser (injection laser) because of its

A) Low cost B) Long wavelength emission C) Low threshold current D) Nonlinear operation

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Answer & Solution

Answer: Option C

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60

Match List-I with List-II and select the correct answer using the options given below:

List-I (Material)	List-II (Properties)
a. Superconductor at very low temperature	1. High frequency
b. Fabric chloride	2. Very small -ve susceptibility
c. Diamond	3. Very high -ve susceptibility
d. Manganese oxide	4. Susceptibility is inversely proportional to +θ

(Here T is temperature of the material in Kelvin. θ is a constant for a material).

A) a-2, b-4, c-3, d-1 B) a-3, b-1, c-2, d-4 C) a-2, b-1, c-3, d-4 D) a-3, b-4, c-2, d-1

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Answer & Solution

Answer: Option B

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Materials And Components MCQ Questions & Answers | ECE