Solid State Physics MCQs Question and Answer in Engineering Physics Page-6 section-1

51.
The energy $$E\left( {\overrightarrow {\bf{k}} } \right)$$ of electrons of wave vector $$\overrightarrow {\bf{k}} $$ in a solid is given by $$E\left( {\overrightarrow {\bf{k}} } \right) = A{k^2} + B{k^4},$$ where A and B are constants. The effective mass of the electron at $$\left| {\overrightarrow {\bf{k}} } \right| = {k_0}$$ is

A. $$Ak_0^2$$

B. $$\frac{{{\hbar ^2}}}{{2A}}$$

C. $$\frac{{{\hbar ^2}}}{{2A + 12Bk_0^2}}$$

D. $$\frac{{{\hbar ^2}}}{{Bk_0^2}}$$

Answer & Solution Discuss in Board Save for Later

52.
The effective density of states at the conduction band edge of Ge is 1.04 × 10¹⁹ cm^-3 at room temperature (300 K). Ge has an optical band gap of 0.66 eV. The intrinsic carrier concentration (in cm^-3) in Ge at room temperature (300 K) is approximately

A. 3 × 10¹⁰

B. 3 × 10¹³

C. 3 × 10¹⁶

D. 6 × 10¹⁶

Answer & Solution Discuss in Board Save for Later

53.
Which one of the following statements is true?

A. Magnetic tapes are made of iron

B. Permanent magnets are made from ferrites

C. Ultrasonic transducers are made from quartz crystals

D. Optoelectronic devices are made from soft ferrites

Answer & Solution Discuss in Board Save for Later

54.
A linear diatomic lattice of lattice constant a with masses M and m (M > m) are coupled by a force constant C. The dispersion relation is given by $${\omega ^2} = C\left( {\frac{{M + m}}{{Mm}}} \right) \pm {\left[ {{C^2}{{\left( {\frac{{m + m}}{{Mm}}} \right)}^2} - \frac{{4{C^2}}}{{Mm}}{{\sin }^2}\frac{{ka}}{2}} \right]^{\frac{1}{2}}}$$
Which one of the following statements is incorrect?

A. The atoms vibrating in transverse mode correspond to the optical branch

B. The maximum frequency of the acoustic branch depends on the mass of the Iighter atom m

C. The dispersion of frequency in the optical branch is smaller than that in the acoustic branch

D. No normal modes exist in the acoustic branch for any frequency greater than the maximum frequency at $$k = \frac{\pi }{a}$$

Answer & Solution Discuss in Board Save for Later

55.
The Hall coefficient R_H of sodium depends on

A. the effective charge carrier mass and carrier density

B. the charge carrier density and relaxation time

C. the charge carrier density only

D. the effective charge carrier mass

Answer & Solution Discuss in Board Save for Later

56.
Which one of the following axes of rotational symmetry is not permissible in single crystals?

A. Two-fold axis

B. Three-fold axis

C. Four-fold axis

D. Five-fold axis

Answer & Solution Discuss in Board Save for Later

57.
The potential in a divalent solid at a particular temperature is represented by a one-dimensional periodic model. The solid should behave electrically as

A. a semiconductor

B. a conductor

C. an insulator

D. a superconductor

Answer & Solution Discuss in Board Save for Later

58.
The c/a ratio for an ideal hexagonal closed packed structure is

A. $$\frac{2}{{\sqrt 3 }}$$

B. √8

C. √5

D. $$\sqrt {\frac{8}{3}} $$

Answer & Solution Discuss in Board Save for Later

59.
In a powder diffraction pattern recorded from a face centred cubic sample using X-rays, the first peak appears at 30°. The second peak will appear at

A. 32.8°

B. 33.7°

C. 34.8°

D. 35.3°

Answer & Solution Discuss in Board Save for Later

60.
The critical magnetic field for a solid in superconducting state

A. does not depend upon temperature

B. increases if the temperature increases

C. increases if the temperature decreases

D. does not depend on the transition temperature

Answer & Solution Discuss in Board Save for Later

Solid State Physics MCQs Question and Answer in Engineering Physics

Answer & Solution

52. The effective density of states at the conduction band edge of Ge is 1.04 × 1019 cm-3 at room temperature (300 K). Ge has an optical band gap of 0.66 eV. The intrinsic carrier concentration (in cm-3) in Ge at room temperature (300 K) is approximately

Answer & Solution

53. Which one of the following statements is true?

Answer & Solution

Answer & Solution

55. The Hall coefficient RH of sodium depends on

Answer & Solution

56. Which one of the following axes of rotational symmetry is not permissible in single crystals?

Answer & Solution

57. The potential in a divalent solid at a particular temperature is represented by a one-dimensional periodic model. The solid should behave electrically as

Answer & Solution

58. The c/a ratio for an ideal hexagonal closed packed structure is

Answer & Solution

59. In a powder diffraction pattern recorded from a face centred cubic sample using X-rays, the first peak appears at 30°. The second peak will appear at

Answer & Solution

60. The critical magnetic field for a solid in superconducting state

Answer & Solution

52.
The effective density of states at the conduction band edge of Ge is 1.04 × 10¹⁹ cm^-3 at room temperature (300 K). Ge has an optical band gap of 0.66 eV. The intrinsic carrier concentration (in cm^-3) in Ge at room temperature (300 K) is approximately

53.
Which one of the following statements is true?

55.
The Hall coefficient R_H of sodium depends on

56.
Which one of the following axes of rotational symmetry is not permissible in single crystals?

57.
The potential in a divalent solid at a particular temperature is represented by a one-dimensional periodic model. The solid should behave electrically as

58.
The c/a ratio for an ideal hexagonal closed packed structure is

59.
In a powder diffraction pattern recorded from a face centred cubic sample using X-rays, the first peak appears at 30°. The second peak will appear at

60.
The critical magnetic field for a solid in superconducting state