In this article, we are going to learn about the previous year’s objective questions with the answers and explanation of Dielectric materials. In this article, there will be previous years’ ESE questions with answers.
Objective Question with Answer for Dielectric Materials For ESE
1. The most important set of specifications of transformer oil includes
- (a) dielectric strength and viscosity
- (b) dielectric strength and flash point
- (c) flash point and viscosity
- (d) dielectric strength, flash point, and viscosity
2. for insulating material, dielectric strength, and dielectric loss should be respectively
- (a) high and high
- (b) low and high
- (c) high and low
- (d) low and low
3. in material characterized by a complex permittivity, the imaginary part is a measure of
- (a) dielectric strength of the material
- (b) energy stored in the electric field
- (c) losses in the material
- (d) energy stored in the magnetic field
4. amplification of ultrasonic waves is possible in a piezoelectric semiconductor under an applied electric field. the basic phenomenon involved is known as
- (a) electrosriction
- (b) acousto-optic interaction
- (c) Acousta electric interaction
- (d) simulated Brillouin scattering
5. The correct sequence of the following in the increasing order of the values of permittivity is
- (a) Air, Vacuum, TaO2, Glass
- (b) Air, Vacuum, Glass, TaO2
- (c) Vacuum, Air, TaO2, Glass
- (d) Vacuum, Air, Glass, TaO2
6. Which material among the following possesses excellent dielectric properties and good reliability for use in making capacitors?
- (a) Silicon monoxide
- (b) Silicon dioxide
- (c) Tin oxide
- (d) Chromium oxide
7. Which of the following materials are piezoelectric?
- (a) Mica and quartz
- (b) Mica, barium titanate and quartz
- (c) mica and diamond
- (d) Barium titanate and quartz
8. Under the influence of an external electric field an insulator undergoes the process of polarization. There are four contributing factors to the total polarization viz. electronic, ionic, orientational, and space charge. At the optical frequencies, the only contribution to the total polarization is the form
- (a) Space charge polarization
- (b) Ionic polarization
- (c) Orientational polarization
- (d) Electronic Polarization
9. The material which has the property of becoming electrically polarized in response to applied mechanical stress is termed as
- (a) Ferroelectric
- (b) Piezoelectric
- (c) Optoelectronic
- (d) Superconducting
10. The electric displacement D in a material is expressed as D = \epsilon E+ d.s where \epsilon is the permittivity, E is the field, s is strain and d is characteristics constant of the material. Which is this material?
- (a) Metal
- (b) Antiferromagnetic material
- (c) Semiconductor
- (d) Piezoelectric material
11. Which one of the following materials is ceramic material?
- (a) Mica
- (b) Zinc sulfide
- (c) Antimony
- (d) Copper
12. The material for the core in a power transformer must have
- (a) high resistivity and low permeability
- (b) the low value of saturation magnetization and high resistivity
- (c) high permeability and low resistivity
- (d) high permeability and high saturation magnetization
13. Ceramic insulators undergo a glazing process to reduce the possibility of electric breakdown. What is the effect of this process?
- (a) it makes the surface non-absorbent
- (b) It makes the surface reflecting
- (c) it makes the surface curvature free
- (d) It makes the surface moist
14. When does BaTiO3 lose its ferroelectric properties?
- (a) Above 0o K
- (b) Above its Curie point
- (c) Above room temperature
- (d) Above its melting point
15. At what condition of the surrounding air, does electro-chemical breakdown occur?
- (a) High temperature and high humidity
- (b) High temperature and low humidity
- (c) Low temperature and high humidity
- (d) Low-temperature and low humidity
16. Why are askerlas not used for transformer or capacitor insulation?
- (a) They have a low dielectric strength
- (b) Their density is high
- (c) They decompose easily giving out toxic gases
- (d) They are highly inflammable
17. Piezoelectricity is the reverse effect of
- (a) Electroluminescence
- (b) Electrostriction
- (c) Peltier effect
- (d) hall effect
18. Potassium Dihydrogen Phosphate (KDP) crystals are used to produce second harmonics of optical frequencies. Which one of the following is an important requirement?
- (a) Their susceptibility should be a constant
- (b) Their susceptibility should be an odd function of the applied electric field.
- (c) Their susceptibility should vary with the square of the applied electric field.
- (d) Their susceptibility should exhibit a peak at the second harmonic frequency
19. The piezoelectric effect is the polarization of a dielectric under the influence of
- (a) Light
- (b) Mechanical stress
- (c) Electrical Stress
- (d) Heat
20. Which one of the following is the remaining grade of paper used in paper capacitors, besides the other two grades of paper-low loss and extra-low loss?
- (a) Strong dielectric
- (b) Regular
- (c) Rough
- (d) High loss
