Objective questions on Dielectric Constants, Dipole moment, Polarization in Material Science
This sets of objective questions or MCQs more focuses on Dielectric Constants, Dipole moment, Polarization, Polarizability, permittivity....
Click here to read part 1 of Dielectric Constants, Dipole moment, Polarization
Click here to read part 2 of Dielectric Constants, Dipole moment, Polarization
This questions and answers may helps in you competitive exams, placements and all university online exams
SET 1 of Dielectric Constants, Dipole moment, Polarization mcqs
Question 1. Photoemissve cell : fire alarms ; photoconductive cell : ?
A. photography
B. calorimetry
C. Automatic door opening
D. None of these
Answer A
Marks 1
Question 2. Photoemissve cell : fire alarms ; photovoltaic cell : ?
A. photography
B. calorimetry
C. Automatic door opening
D. Solar panels
Answer D
Marks 1
Question 3. Piezoelectricity : mechanical force ; ferrroelectricity : ?
A. temperature
B. light intensity
C. pressure
D. spontaneous polarization
Answer D
Marks 1
Question 4. Ferroelectricity : capacitors; pyroelectricity : ?
A. Ultrasound waves
B. Infrared detectors
C. transducers
D. gas lighters
Answer B
Marks 1
Question 5. The dielectric loss does not vary with
A. applied voltage
B. frequency
C. capacitance
D. inductance
Answer D
Marks 1
Question 6. If relative permittivity of argon atom is 1.0024 at NTP & N = 2.7 x1025 atoms / m3.Then electronic polarizability of argon atom will be
A. 7.9 x 10 -40 F.m2
B. 7.9 x 10 -4 F.m2
C. 7.9 x 10 -10 F.m2
D. 7.9 x 10 -14 F.m2
Answer A
Marks 1
Question 7. High dielectric constant materials is must for _____ .
A. generators
B. motors
C. switch gears
D. capacitors
Answer D
Marks 1
Question 8. Polarization per unit applied electric field is ____
A. Polarization
B. Dielectric constant
C. Magnetic susceptibility
D. electric susceptibility
Answer D
Marks 1
Question 9. The energy band gap size for dielectric is in the range ____ .
A. 1 -2 eV
B. 2 -3 eV
C. 3- 4 eV
D. 4 - 5 eV
Answer A
Marks 1
Question 10. Dielectrics are -----.
A. Metals
B. Semiconducting materials
C. insulating materials
D. magnetic materials
Answer C
Marks 1
Question 11. In dielectrics, loss is represented as
A. Hysteresis loss
B. Eddy current loss
C. loss tangent
D. None of these
Answer C
Marks 1
Question 12. Emission of electron in vaccum diode, is achieved by ______ .
A. electrostatic field
B. magnetic field
C. heating
D. electron bombardment
Answer C
Marks 1
Question 13. Ceramics are -----.
A. metals
B. semiconducting materials
C. insulating materials
D. magnetic materials
Answer C
Marks 1
Question 14. Number of photo electrons emitted from a metal, in photo electric emission are ____.
A. Directly proportional to intensity of light
B. Directly proportional to square of intensity of light
C. inversely proportional to intensity of light
D. inversely proportional to square of intensity of light
Answer A
Marks 1
Question 15. When sodium crystal is subjected to an electric field of 2000 V/m and the resultant polarization is 4.3 x 10-8 c/m2; then the relative permittivity of sodium crystal is
A. 34.29
B. 3.429
C. 0.3429
D. 342.9
Answer B
Marks 1
Question 16. Number of photo electrons emitted with range of velocities ______.
A. Increases with radiation frequency and independent of radiation intensity
B. Decreases with increases with radiation frequency and independent of radiation intensity
C. decreases with radiation frequency and independent of radiation intensity
D. Decreases with increases with radiation frequency and dependent of radiation intensity
Answer A
Marks 1
Question 17. Optical fibre is used in _______ .
A. Circuit breakers
B. Frequency measurement
C. Transmission
D. None of these
Answer B
Marks 1
Question 18. Piezoelectric material served , as a source of ______ waves.
A .ultrasonic
B. Micro
C. resonant
D. music
Answer A
Marks 1
Question 19. Which of the following material is not piezoelectric material?
A. glass
B. quartz
C. Rochelle salt
D. Barium titanate
Answer A
Marks 1
Question 20. The capacitors for power factor correction are rated in terms of
A. kV
B. kW
C. kVAR
D. VA
Answer C
Marks 1
Question 21. The dielectric loss tangent can be measured by using __________.
A .Schering bridge
B. Anderson’s bridge
C. Maxwell’s bridge
D. none of these
Answer A
Marks 1
Question 22. A dielectric material can be polarized by applying _____ field to it.
A. magnetic field
B. electric field
C. gravitational
D. None of these
Answer B
Marks 1
Question 23. In the absence of external electric field, the electric dipoles in a dipolar substance are ---
A. parallel
B. randomly oriented
C. alternatively anti- parallel
D. None of these
Answer B
Marks 1
Question 24. Materials which can store electrical energy are called as ----- materials.
A. magnetic
B. dielectric
C. insulating
D. superconducting
Answer B
Marks 1
Question 25. If relative permittivity of argon atom is 1.0024 at NTP & N = 2.4 x1025 atoms / m3.Then electronic polarizability of argon atom will be
A. 8.854 x 10 -40 F.m2
B. 8.854 x 10 -14 F.m2
C. 8854 x 10 -30 F.m2
D. 8.854 x 10 -20 F.m2
Answer A
Marks 1
Question 26. The dielectric loss tangent can be given by __________.
A. ( G/B )
B. ( IR / IC )
C. (1/ ωCR )
D. All of these
Answer D
Marks 1
Question 27. Dielectric constant of vacuum is
A. infinity
B. zero
C. 10
D. one
Answer D
Marks 1
Question 28. What types of dielectric are best suited for use in a high temperature applications?
A. Cotton, poly-tetra-fluoro-ethylene and oiled paper
B. FEP, silicone rubber and extruded poly-tetra-fluoro-ethylene
C. Rubber, poly-tetra-fluoro-ethylene and silk
D. Oiled paper, FEP and rubber
Answer B
Marks 1
Question 29. What is the definition, that best describes a dielectric material?
A. material that has a very high resistance and stores a charge
B. material that has a very low resistance and stores a charge
C. material that has a very low dielectric strength
D. material that has a very high conductivity
Answer A
Marks 1
Question 30. Which of the following statements is true for relative permittivity ?
A. It is dimensionless
B. Its value for all substances is more than one
C. It is equal to unity for vacuum
D. all of these
Answer D
Marks 1
Click here to read part 1 of Dielectric Constants, Dipole moment, Polarization
Click here to read part 2 of Dielectric Constants, Dipole moment, Polarization
All questions are important any exam point of view so read carefully.
