Explore topic-wise MCQs in Engineering Physics.

This section includes 6 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering Physics knowledge and support exam preparation. Choose a topic below to get started.

1.

For semiconductors, the resistivity is inversely proportional to the temperature for semiconducting materials.

A. True
B. False
Answer» B. False
Discussion
2.

The conductivity of germanium at 20 C is 2/ohm m. What is its conductivity at 40 C? Eg=0.72eV

A. 1.38 10<sup>-23</sup>/Ohm m
B. 1.0002/Ohm m
C. 293/Ohm m
D. 313/Ohm m
Answer» C. 293/Ohm m
Discussion
3.

A silicon plate of thickness 1mm, breadth 10mm and length 100mm is placed in a magnetic field of 0.5 Wb/m2 acting perpendicular to its thickness. If 10-3 A current flows along its length, calculate the Hall voltage developed, if the Hall coefficient is 3.66 104 m3/Coulomb.

A. 1.83 10<sup>-3</sup> Volts
B. 3.66 10<sup>-4</sup> Volts
C. 0.5 Volts
D. 25.150 Volts
Answer» B. 3.66 10<sup>-4</sup> Volts
Discussion
4.

The intrinsic carrier density at room temperature in Ge is 2.37 1019/m3. If the electron and hole mobilities are 0.38 and 0.18 m2/Vs respectively. Calculate its resistivity.

A. 0.18ohm m
B. 0.460ohm m
C. 0.4587ohm m
D. 0.709ohm m
Answer» E.
Discussion
5.

A semiconducting crystal 12mm long, 5mm wide and 1mm thick has a magnetic flux density of 0.5Wb/m2 applied from front to back perpendicular to largest faces. When a current of 20mA flows length wise through the specimen, the voltage measured across its width is found to be 37 V. What is the Hall coefficient of this semiconductor?

A. 37 10<sup>-6</sup> m<sup>3</sup>/C
B. 3.7 10<sup>-6</sup> m<sup>3</sup>/C
C. 3.7 10<sup>6</sup> m<sup>3</sup>/C
D. 0
Answer» C. 3.7 10<sup>6</sup> m<sup>3</sup>/C
Discussion
6.

Which method can be used to distinguish between the two types of carriers?

A. Hall effect
B. Rayleigh method
C. Doppler effect
D. Fermi effect
Answer» B. Rayleigh method
Discussion