Physics of Metals in Metallurgy MCQ Questions and Answers

61

In an ideal HCP packing, the c/a ratio is

A) 1.225 B) 1.414 C) 1.633 D) 1.732

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

62

Match each material in Group I with a bond type in Group II.

Group I	Group II
P. Silicon	1. Metallic bonding
Q. Copper	2. Covalant bonding
R. Sodium chloride	3. Ionic bonding
	4. Vander-Wallis bonding

A) P-2, Q-1, R-4 B) P-1, Q-3, R-1 C) P-4, Q-1, R-3 D) P-2, Q-1, R-3

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

63

Dissociation of a dislocation into two particals in an FCC metal is given by the following equation.
$$\frac{a}{2}\left[ {1\overline 1 1} \right] \to \frac{a}{6}\left[ {2\overline 1 1} \right] + \frac{a}{6}\left[ {1\overline 2 \overline 1 } \right]$$
On which plane do these two partial dislocations lie?

A) $$\overline 1 11$$ B) -111 C) $$\left( {1\overline 1 1} \right)$$ D) $$\left( {11\overline 1 } \right)$$

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

64

The density and associated crystallinity for two polypropylene samples are as follows:

density, g/cm³	crystallinity, %
1.20	50
1.44	80

Density of totally amorphous polypropylene is

A) 0.64 B) 0.74 C) 0.84 D) 0.94

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

65

The majority charge carriers in p-type silicon are

A) Free electrons B) ions C) conduction electrons D) holes

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

66

An edge dislocation is present in α-Fe. Atomic diameter of iron atom is 0.25 nm and its shear modulus is 70 GPa. Modulus of the Burgers vector (in nm) is

A) 0.125 B) 0.25 C) 0.5 D) 0.625

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

67

Which one of the following reactions is fcc/bcc crystals with lattice parameter 'a' is energetically favourable?

A) $$\frac{a}{2}\left[ {\overline 1 10} \right] + \frac{a}{2}\left[ {0\overline 1 \overline 1 } \right]$$ B) $$\frac{a}{2}\left[ {111} \right] + \frac{a}{2}\left[ {11\overline 1 } \right]$$ C) $$\frac{a}{2}\left[ {115} \right] + \frac{a}{2}\left[ {11\overline 1 } \right]$$ D) $$\frac{a}{2}\left[ {111} \right] + \frac{a}{2}\left[ {111} \right]$$

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

68

For a simple cubic unit cell with unit vectors, i, j and k, the angle between the lattice vector [100] and [111] in degrees is

A) 35.2 B) 54.7 C) 60 D) 90

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

69

The electrical conductivity of pure silicon at 300 K is 4.34 × 10^-4 (Ωm)^-1 and at 500 K, it is 2.15(ΩM)^-1. Given that the Boltzman constant, R = 8.6 × 10^-5 eV .K^-1, the band energy gap is . . . . . . . . eV.

A) 0.65 B) 1.1 C) 1.5 D) 2.2

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

70

A peak in the X-ray diffraction pattern is observed at 2θ = 78°, corresponding to [311] planes of an fcc metal, when the incident beam has a wavelength of 0.154 nm. The lattice parameter of the metal is approximately

A) 0.6 nm B) 0.4 nm C) 0.3 nm D) 0.2 nm

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

Physics of Metals in Metallurgy MCQ Questions and Answers | Metallurgical Engineering