Materials And Components MCQ Questions & Answers

21

A vacuum parallel plate capacitor is charged. The field between the plates is 2 × 10⁴ V/m. If the space between the plates is filled with a material of relative dielectric constant of 10.0, then the value of the field in the dielectric will be

A) 2 × 10³ V/m B) $$\frac{2}{{\sqrt {10} }} \times {10^{ - 4}}{\text{ V/m}}$$ C) $$2 \times \sqrt {10} \times {10^4}{\text{ V/m}}$$ D) 2 × 10⁵ V/m

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Answer & Solution

Answer: Option A

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22

Magnetic field of Earth has no vertical component at

A) Magnetic poles B) Magnetic equator C) Latitude 450 D) Longitude 450

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Answer & Solution

Answer: Option B

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23

Material in superconducting state have the property of

A) Absorbing magnetic field B) Repelling magnetic field C) Absorbing electric field D) Repelling electric field

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Answer & Solution

Answer: Option B

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24

The crystal in which atoms are chemically highly inactive and they do not form compounds with other atoms is

A) Ionic crystal B) Metal C) Valence crystal D) Vander waals crystal

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Answer & Solution

Answer: Option D

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25

Resistivity of iron and nickel is of the order of

A) 10^-9ohm m B) 10^-7ohm m C) 10^-6ohm m D) 10^-3ohm m

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Answer & Solution

Answer: Option B

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26

The temperature at which a material becomes a glassy solid is called

A) melting temperature B) recrystallization temperature C) glass transition temperature D) freezing temperature

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Answer & Solution

Answer: Option C

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27

Elements can reach a stable atomic structure by

A) collision between atoms B) losing electrons only C) gaining electrons only D) losing or gaining or sharing electrons

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Answer & Solution

Answer: Option D

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28

The first critical condition at which free electrons are diffracted in an FCC crystal would occur at which one of the following values of the wave number 'k'? ('a' is lattice parameter)

A) $$\frac{2}{a}$$ B) $$\frac{{\pi a}}{{\sqrt 3 }}$$ C) $$\frac{\pi }{a}$$ D) $$\frac{{\sqrt 3 \pi }}{a}$$

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Answer & Solution

Answer: Option D

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29

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

List-I	List-II
a. Ferrite	1. Meissner effect
b. Superconductor	2. Faraday effect
c. Quartz	3. Low sensitivity and high stability
d. Iron	4. Piezoelectricity

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

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Answer & Solution

Answer: Option B

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30

Which of the following is the Fermi function f(E)?

A) $$\frac{1}{{1 + {e^{\frac{{E - {E_F}}}{{KT}}}}}}$$ B) $$\frac{1}{{1 - {e^{\frac{{E - {E_F}}}{{KT}}}}}}$$ C) $$\frac{1}{{1 + {e^{\frac{{{E_F} - E}}{{KT}}}}}}$$ D) $$\frac{1}{{1 - {e^{\frac{{{E_F} - E}}{{KT}}}}}}$$

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Answer & Solution

Answer: Option A

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Materials And Components MCQ Questions & Answers | ECE