# 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....

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## SET 1 of Dielectric Constants, Dipole moment, Polarization mcqs

Question 1. The value of tanδ is negative for ----- circuits.
A resistive - capacitive
B resistive - inductive
C inductive- capacitive
D none of these

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Question 2. Two charges equal in magnitude but opposite in polarity and separated by distance(d)
constitute a ______________ .
A dipole
B polarization
C dielectric constant
D None of these

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Question 3. The dielectric loss is given by
A P = 2πfCV2 tanδ
B P = 2πf2CV / ωCR
C P = (α.E2) / 2
D All of these

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Question 4. The value of permittivity of free space is
A 8.854 x 10-11 F/m
B 8.854 x 10-12 F/m
C 8.854 x 10-13 F/m
D 8.854 x 10-10 F/m

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Question 5.In case of thermocouple materials, the voltage generated is ____
A voltage magnitude is in milivolts
B permanent in nature
C DC in nature
D all of these

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Question 6.When sodium crystal is subjected to an electric field of 1000 V/m and the resultant polarization is 4.3 x 10-8 c/m2 ; then the relative permittivity of sodium crystal is
A 586
B 5.86
C 0.586
D 58.6

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Question 7.Debye is the unit for
A polarization
B dipole moment
C dielectric constant
D None of these

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Question 8.Units of polarization and polarizability respectively are
A c/m2 , Fm2
B c/m2 , F/m2
C cm2 , Fm2
D cm2 , F/m2

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Question 9.In case of Pyro-electric materials, the voltage generated is ____
A temporary
B permanent
C AC in nature
D none of these

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Question 10.The materials used for Solar PV depend on _______ .
A cost or Rs / watts
B applications
C availability of space
D all of the above

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## SET 2 of Dielectric Constants, Dipole moment, Polarization mcqs

Question 11. Dielectric constant for monoatomic gas is ____ (approx).
A 0
B 1
C 2
D 3

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Question 12.Dielectric loss indicates quality of____ materials.
A conducting
B dielectric
C semiconducting
D magnetic

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Question 13.In piezoelectric materials, _____ energy is converted into electrical energy.
A solar
B mechanical
C heat
D chemical

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Question 14. In orientational polarization, rotation of the permanent dipole moment is _____ the direction of the applied field.
A in the
B parallel
C opposite
D perpendicular

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Question 15. If the susceptibility of carbon dioxide atom is 0.974 x 10-3 at NTP & N = 2.8 x1025 atoms / m3 , then electronic polarizability of CO2 atom will be
A 3.078 x 10 -14 F.m2
B 3.078 x 10 -10 F.m2
C 3.078 x 10 -40 F.m2
D 3.078 x 10 -4F.m2

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Question 16.The pyro-electric materials have ____
A dipole polarization
B electronic polarization
C spontaneous polarization
D both A and D

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Question 17.The ----- an example of a photo emissive cell.
A Photo transistor
B Photo diode
C Photo multiplier
D LDR

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Question 18.For inductive winding circuits, tanδ (dielectric loss tangent) is ___ , while for capacitive circuits, it is _________.
A negative, negative
B negative , positive
C positive , negative
D positive , positive

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Question 19.Thin film PV cells are manufactured by ______
A Czocharlski method
B Casting process
C CVD technique
D both a and b

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Question 20. Piezoelectricity : quartz ; ferroelectricity : ?
B PzT type of ceramic
C Sodium nitrate
D None of these

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## SET 3 of Dielectric Constants, Dipole moment, Polarization mcqs

Question 21.The photoconductive cell consists of a thin film of _____
B Lithium sulphate
C Quartz
D Barium sulphate

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Question 22.Ferroelectricity : barium titanate ; Piezoelectricity : ?
A Rochelle salt
B PzT type ceramic
C Sodium nitrate
D None of these

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Question 23.Piezoelectricity : mechanical force ; pyroelectricity : ?
A temperature
B light intensity
C pressure
D Spontaneous polarization

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Question 24.Piezoelectricity : gas lighters ; pyroelectricity : ?
A ultrasound waves
B Infrared detectors
C transducers
D capacitors

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Question 25.If a capacitor of 5 µF is applied with voltage of 50 kV at a frequency of 50Hz and its dielectric loss tangent is 0.002 ; then the dielectric loss will be
A 7853.98 W
B 785.398 J
C 785.398 W
D 78.5398 W

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Question 26.The ------ is the type of photoelectric cells.
A photoconductive cells
B photoemissive cells
C photovoltaic cells
D All of these

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Question 27.The dielectric loss tangent varies in square proportion of
A Applied voltage
B frequency
C capacitance
D All of these

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Question 28.Pyroelectricity : Infrared detectors ; Piezoelectricity : ?
A Ultrasound waves
B Strain gauges
C Memory devices
D capacitors

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Question 29.'tanδ' is known as
A Dissipation factor
B Dielectric loss tangent
C Power factor of dielectric
D All of these

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Question 30.Photoemissve cell : fire alarms :: photoconductive cell : ?
A photography
B calorimetry
C Automatic door opening
D None of these

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