MSBTE 'K' Scheme 1st Semester Basic Science: "Physics" Practice MCQs with Answers PDF. This MCQs is base on your MSBTE Basic Science Syllabus All Units and All Topics Covered in this Section.
- Units and Measurements MCQs with Answers
- Electricity, Magnetism and Semiconductors MCQs with Answers
- Thermometry and Fiber Optics MCQs with Answers
1. Units
and Measurements
1. The symbol to represent
“Amount of Substance” is ________
a)
K
b)
A
c)
Cd
d) mol
Answer: (d) mol
Explanation: The symbol to
represent Amount of Substance is mol.
2. Which among the following
is the Supplementary Unit——–
a)
Mass
b)
Time
c) Solid
angle
d)
Luminosity
Answer: (c) Solid angle
Explanation: Supplementary
units are plane angles and solid angles. Other units mentioned are base units.
3. What is the unit of solid
angle?
a)
second
b) Steradian
c)
kilogram
d)
candela
Answer: (b) Steradian
Explanation: Steradian is
the unit of solid angle.
4. AU is the unit of
________
a)
Astronomy Unit
b) Astronomical
unit
c)
Astrological Unit
d)
Archaeological Unit
Answer: (b) Astronomical unit
Explanation: Astronomical
unit is the average distance of the Sun from the Earth. It is represented by
the symbol AU.
5. Dimensions of kinetic
energy is the same as that of ________
a)
Acceleration
b)
Velocity
c) Work
d)
Force
Answer: (c) Work
Explanation: Dimensions of
kinetic energy and work are the same.
6.The pair of quantities
having the same dimensions is
(a) displacement, velocity
(b) time, frequency
(c) wavelength, focal length
(d) force, acceleration
Answer:(c) wavelength, focal length
7.Average distance of the Sun
from the Earth
(a) light year
(b) astronomical unit
(c) fermi
(d) parsec
Answer: (b) astronomical unit
8.The number of significant
figures in the number 0.0028 is,
(a) 2
(b) 3
(c) 4
(d) 5
Answer: (a) 2
9.Which of the following is
not the unit of time
(a) second
(b) minute
(c) month
(d) light year
Answer:(d) light year
10.If x = a + bt + ct2, where
x is in metre and t in second, then what is the unit of ‘c’?
(a) m/s
(b) m/s2
(c) kgm/s
(d) m2/s
Answer:(b) m/s2
11.The base quantity among the
following is,
(a) Speed
(b) area
(c) length
(d) weight
Answer:(c) length
12.Dimensional analysis can be
applied to
(a) to check the correctness
of a physical equation.
(b) to derive the
relationship between different physical quantities.
(c) to convert a physical
quantity from one system of units to other.
(d) All of the above
Answer:(d) All of the above
13.Which of the following
physical quantity has the dimensional formula [M1L2T-3]
(a) work
(b) power
(c) work
(d) impulse
Answer:(b) power
14.The dimensions of universal
gravitational constant is
(a) [M-1L3T-2]
(b) [M1L1T-2]
(c) [M-1L2T-2]
(d) [M1L-1T-1]
Answer:(a) [M-1L3T-2]
15.Which of the following is
dimensionless
(a) force/acceleration
(b) velocity/acceleration
(c) volume/area
(d) energy/work
Answer:(d) energy/work
16. Farad is the unit of ________
a)
Luminosity
b)
Wavelength
c) Permittivity
d)
Inertia
Answer: (c) Permittivity
Explanation: Permittivity is
the unit of Farad.
17. Electron volt is a unit
of
a)
Luminosity
b)
Frequency
c)
Force
d) Energy
Answer: (d) Energy
Explanation: One of the
units of energy is electron volt.
18. Joule second is the unit
of
a)
Force
b) Angular
momentum
c)
Energy
d)
Power
Answer: (b) Angular momentum
Explanation: Angular
momentum is also known as rotational momentum. The total angular momentum of a
closed system remains constant.
19. The smallest value which
is measured using an instrument is known as ________
a)
Absolute count
b) Least
count
c)
Round off value
d)
Minimum count
Answer: (b) Least count
20. Which is the system of
unit
a)
SMS system
b)
MKP system
c) FPS
System
d)
CJS System
Answer: (c) FPS System
Explanation: FPS System is
one of the systems of units. Foot, Pound, and Second (FPS system).
21. Light year is a unit of
a)
time
b) distance
c)
sunlight intensity
d)
mass
Answer: Distance
22 The dimensions of Kinetic
energy is same as that of
a)
Force
b)
Pressure
c) Work
d)
Momentum
Answer: Work
23 There are 20 divisions in
4 cm of the main scale. The vernier scale has 10 divisions. The least count of
the instrument is
a)
0.05 cm
b)
0.5 cm
c)
5.0 cm
d) 0.005
cm
Answer: 0.005 cm
24 One kilometer is equal to
how many miles?
a)
0.84
b)
0.5
c)
1.6
d) 0.62
Answer: 0.62
25 The mass and volume of a
body are 4.237 g and 2.5 cm3, respectively. The density of the material of the
body in correct significant figures is
a)
1.6048 g cm-3
b)
1.69 g cm-3
c) 1.7 g
cm-3
d)
1.695 g cm-3
Answer: 1.7 g cm-3
26 Measure of two quantities
along with the precision of respective measuring instrument is
a)
= 2.5 m s-1 ± 0.5 ms-1
b)
= 0.10 s ± 0.01 s The value of A B will be A (0.25 ±
0.08) mB (0.25 ± 0.5) m
c) (0.25 ± 0.05) mD (0.25 ± 0.135) m
Answer: (0.25 ± 0.08) m
27 Electron volt is a unit
of
a)
Potential difference
b)
Electric current
c)
Electronic charge
d) Energy
Answer: Energy
28 Which of the following
quantities is expressed as force per unit area?
a)
Work
b)
Area
c)
Volume
d) Pressure
Answer: Pressure
29 A vernier caliper has its
main scale of 10 cm equally divided into 200 equal parts. If vernier scale of
25 divisions coincides with 12 mm on the main scale. The least count of the
instrument is
a)
0.020 cm
b) 0.002
cm
c)
0.010 cm
d)
0.001 cm
Answer: 0.002 cm
30 g cm s–2 stands for the unit of
a)
Energy
b) Force
c)
Momentum
d)
Acceleration
Answer: Force
31 The number of significant
figures in 0.00040 m is
a)
1
b) 2
c)
3
d)
4
Answer: 2
32 With due regard for
significant figures, (12.5)2 =
a)
156.250
b)
156.25
c)
156.2
d) 156
Answer: 156
33 The ratio of the height
of a man to the radius of the earth is of the order of
a)
10–9
b) 10–7
c)
10–5
d)
10–3
Answer: 10–7
34 One torr is equal to
a)
1 Nm–2
b) 1 mm of
Hg
c)
1 atm pressure
d)
1 cm of Hg
Answer: 1 mm of Hg
35 If momentum (P ), area
(A) and time ( T ) are taken to be fundamental quantities, then energy has the
dimensional formula
a)
(P1 A-1 T1)
b)
(P2 A1 T1)
c)
(P2 A-1/2 T1)
d) (P1 A1/2 T-1)
Answer: (P1 A1/2 T-1)
36 Which of the following
measurements is most precise?
a) 5.00 mm
b)
5.00 cm
c)
5.00 m
d)
5.00 km
Answer: 5.00 mm
37 The number of significant
figures in 0.06900 is
a)
5
b) 4
c)
2
d)
3
Answer: 4
38 One nanometer is equal to
a)
10-6 m
b)
10-8 m
c) 10-9 m
d)
10-5 m
Answer: 10-9 m
39) At 4° C, the density of
water is equal to
a)
10-3 kg m-3
b)
10-2 kg m-3
c)
10 kg m-3
d) 103 kg
m-3
Answer: 103 kg m-3
40) The dimensional formula
for Planck’s constant is
a)
[MLT]
b) [ML2T-1]
c)
[M2L2T-1]
d)
[ML1T-1]
e) Answer: [ML2T-1]
50. The internationally
accepted reference standard is called
a) Unit
b) Measurements
c) Both a and b
d) None
Ans: a) unit
52.The units for the fundamental
or base quantities are called
a) Base units
b) Fundamental units
c) Both a and b
d) None
Ans: c) both a and b
53) The units which are
obtained for the derived quantities are called
a) Fundamental units
b) Base units
c) Derived units
d) None
Ans: c) derived units
54) The complete set of
derived units and base units is called as
a) Fundamental units
b) Base units
c) System of units
d) Nine
Ans: c) system of units
55) CGS system stands for
a) Meter, gram, second
b) Centimetres, kilogram,
second
c) Centimetres, gram, second
d) None
Ans: c) centimetres, gram, second
56) MKS system stands for
a) Centimetres, gram, second
b) Meters, kilogram, second
c) Meter, gram, second
d) None
Ans: b) meters, kilogram, second
57) The system of units
which is internationally accepted for measurement is called as
a) MKS system
b) CGS system
c) FPS system
d) SI system
Ans: d) SI system
58) In SI system, length is
measured in
a) Centimetres
b) Meters
c) Millimetre
d) Micrometre
Ans: b) meter
59) In SI system, mass is
measured in
a) Kilogram
b) Gram
c) Pound
d) None
Ans: a) kilogram
60) In SI system, ampere is
the unit of
a) Charge
b) Potential
c) Electric current
d) None
Ans: c) electric current
61) In SI system,
temperature is measured in
a) Kelvin
b) Fehrenite
c) Celsius
d) None
Ans: a) Kelvin
62) In SI system, amount of
substance is measured in
a) Kilomole
b) Mole
c) Both a and b
d) None
Ans: b) mole
63) In SI system, luminous
intensity is measured in
a) Ampere
b) Kelvin
c) Candela
d) None
Ans: c) candela
64) The large distances like distance of a planet
from the earth is measured by
a) Meter scale
b) Parallax method
c) Both a and b
d) None
Ans: b) Parallax method
65) 1fermi =
a) 10-15m
b) 10-13m
c) 10-12m
d) 10-16m
Ans: a) 10-15m
66) 1 angstroms=
a) 10-8m
b) 10-9m
c) 10-10m
d) 10-15m
Ans: c) 10-10m
67) 1 astronomical unit=
a) 1.496*10-11m
b) 1.496*1011m
c) 1.496*10-12m
d) 1.496m
Ans: b) 1.496*1011m
68) 1 light year=
a) 9.46*1015m
b) 9.46*10-15m
c) 9.46m
d) 9.46km
Ans: a) 9.46*1015m
69) The mass of an atom is
expressed in
a) Gram
b) Kilogram
c) Unified atomic mass unit
d) Milligrams
Ans: c) unified atomic mass unit
70) 1unified atomic mass
unit =
a) 1.66*1027kg
b) 1.66*10-27g
c) 1.66*10-27kg
d) None
Ans: c) 1.66*10-27kg
71) The size of the proton
is of the order of
a) 10-14m
b) 10-15m
c) 10-16m
d) 10-13m
Ans: b) 10-15m
72) Size of the atomic
nucleus is of the order of
a) 10-13m
b) 10-14m
c) 10-15m
d) 10-16m
Ans: b) 10-14m
73) Size of the hydrogen
atom is of the order of
a) 10-15m
b) 10-14m
c) 10-10m
d) 10-9m
Ans: c) 10-10m
74) The length of the
typical virus is if the order of
a) 10-10m
b) 10-8m
c) 10-9m
d) 10-6m
Ans: b) 10-8m
75) The radius of the earth
is
a) 107m
b) 108m
c) 109m
d) 1010m
Ans: a) 107m
76) Distance of the moon
from the earth is
a) 107m
b) 1010m
c) 108m
d) 109m
Ans: c) 108m
77) Distance of the sun from
the earth is
a) 109m
b) 1010m
c) 10-11m
d) 1011m
Ans: d) 1011m
78) The uncertainty in the
measuring instruments is called
a) Uncertainty Ezoic
b) Error
c) Both a and b
d) None
Ans: b) error
79) Those errors which tends
to be in one direction are called as
a) Errors
b) Systematic errors
c) Both a and b
d) None
Ans: b) systematic errors
80) The errors which arises
from the errors due to imperfect design or calibration of the measuring
instruments are called
a) Systematic errors
b) Instrumental errors
c) Personal errors
d) None
Ans: b) instrumental errors
81) The errors arises due to
individual bias, lack of proper setting of apparatus or individuals
carelessness while taking observations are called
a) Systematic errors
b) Fundamental errors
c) Personal errors
d) None
Ans: c) Personal errors
82) The errors which occurs irregularly
and hence random with respect to size and sign are called
a) Systematic errors
b) Personal errors
c) Random errors
d) None
Ans: c) random errors
83) The smallest value that
can be measured by the measuring instrument is called as
a) Count
b) Least count
c) Both a and b
d) None
Ans: b) least count
84) The errors associated
with the resolution of the instrument is called as
a) Personal errors
b) Instrumental errors
c) Least count errors
d) None
Ans: c) least count errors
85) The magnitude of the
difference between the individual measurement and the true value of the
quantity is called the
a) Least count errors
b) Absolute error of the
measurement
c) Both a and b
d) None
Ans: b) absolute error of the measurements
86) The arithmetic mean of
all the absolute errors taken is called as
a) Average absolute error
b) Mean absolute error
c) Absolute error
d) None
Ans: b) mean absolute error
87) The ratio of the mean
absolute error to the mean value of the quantity measured is called as
a) Absolute error
b) Mean absolute error
c) Relative error
d) None
Ans: c) relative error
88) When relative error is
expressed in per cent then it is called as
a) Absolute error
b) Mean absolute error
c) Percentage error
d) None
Ans: c) percentage error
89) Error in case of a
measured quantity
a) Raised to power
b) Not raised to power
c) Both a and b
d) None
Ans: a) raised to power
90) The reliable digits plus
the first uncertain digit are known as
a) Significant digits
b) Significant figures
c) Both a and b
d) None
Ans: c) both a and b
91) If the units of the
quantity are changed then it’s —– down not changes
a) Significant figures
b) Significant digits
c) Both a and b
d) None
Ans: c) both a and b
92) All the non zero digits
are
a) Not significant
b) Significant
c) Both a and b
d) None
Ans: b) significant
93) All the zeroes between
two non zero digits are
a) Significant
b) Not significant
c) Both a and b
d) None
Ans: a) significant
94) If the number is less
than 1, the zeroes on the right of decimal point but to the left of the first
non zero digit are
a) Significant
b) Not significant
c) Both a and b
d) None
Ans: b) not significant
95) The terminal or trailing
zeroes in a number without a decimal point are
a) Significant
b) Not significant
c) Both a and b
d) None
Ans: b) not significant
96) The trailing zero in a
number with a decimal point are
a) Significant
b) Not significant
c) Both a and b
d) None
Ans: a) significant
97) Preceding digit is raised
by ___ if the insignificant digit to be dropped is more than 5, and is left
unchanged if the later is less than 5.
a) 1
b) 2
c) -1
d) None
Ans: a) 1
98) If the preceding digit is
even then the insignificant digit is
a) Raised by 1
b) Simply dropped
c) Both a and b
d) None
Ans: b) simply dropped
99) If the preceding digit is
odd then the preceding digit is
a) Simply dropped
b) Raised by 1
c) Not raised by 1
d) None
Ans: b) raised by 1
100) An equation obtained by equating
physical quantity with its dimensional formula is called
a) Dimensional formula
b) Dimensional equation
c) Both a and b
d) None
Ans: b) dimensional equation
2. Electricity
Magnetism and Semiconductors
1.Tesla is a unit of
a)
Field strengthm
b)
Inductance
c) Flux
density
d)
Flux
Correct Answer : (C)
2.A permeable substance is
one
a)
Which is a good conductor
b)
Which is a bad conductor
c)
Which is a strong magnet
d) Through
which the magnetic lines of force can pass very easily
Correct Answer : (D)
3.The materials having low
retentivity are suitable for making
a)
Weak magnet
b) Temporary
magnet
c)
Permanent magnet
d)
None of the above
Correct Answer : (B)
4.A magnetic field exits
around
a)
Iron
b)
Copper
c)
Aluminium
d) Moving
charge
Correct Answer : (D)
5.A magnet does not attract
a)
Cobalt
b)
Nickel
c) Copper
d)
Iron
Correct Answer : (C)
6.Aluminium and platinum are
???. Materials
a)
Ferromagnetic
b)
Diamagnetic
c) Paramagnetic
d)
None of the above
Correct Answer : (C)
7.Ferrites are ________
materials.
a)
Paramagnetic
b)
Diamagnetic
c) Ferromagnetic
d)
None of the above
Correct Answer : (C)
8.Air gap has ?????.
reluctance as compared to iron or steel path
a)
Little
b) Lower
c)
Higher
d)
Zero
Correct Answer : (B)
9.The direction of magnetic
lines of force is
a)
From south pole to north pole
b) From
north pole to south pole
c)
From one end of the magnet to another end
d)
None of the above
Correct Answer : (B)
10.Which of the following is
the vector quantity?
a)
Relative permeability
b) Magnetic
field intensity
c)
Flux density
d)
Magnetic potential
Correct Answer : (B)
11.The two conductors of a
transmission line carry equal current in opposite directions. The force on each
conductor is
a)
proportional to I
b)
proportional to the square of currentproportional to
distance between the conductors
c)
inversely proportional to the square of current
d) proportional
to the square of current
Correct Answer : (D)
12. A material which is
slightly repelled by a magnetic field is known as
a)
Ferromagnetic material
b) Diamagnetic
material
c)
Paramagnetic material
d)
Conducting material
Correct Answer : (B)
13.Indicate which of the
following material does not retain magnetism permanently
a) Soft
iron
b)
Stainless steel
c)
Hardness steel
d)
None of the above
Correct Answer : (A)
14.The main constitute of
permalloy is
a)
Cobalt
b)
Chromium
c) Nickel
d)
Tungsten
Correct Answer : (C)
15.The use of permanent
magnet is not made in
a)
Magnetos
b)
Energy meters
c) Transformers
d)
Loud-speakers
Correct Answer : (C)
16.Paramagnetic materials
have relative permeability
a)
Slightly less than unity
b)
Equal to unity
c) Slightly
more than unity
d)
Equal to that ferromagnetic material
Correct Answer : (C)
17.Degaussing is the process
of
a)
Removal of magnetic impurities
b)
Removing gases from the materials
c)
Remagnetising metallic parts
d) Demagnetising
metallic parts
Correct Answer : (D)
18.Substances which have
permeability less than the permeability of free space are known as
a)
Ferromagnetic
b)
Paramagnetic
c) Diamagnetic
d)
Bipolar
Correct Answer : (C)
19. Which among the
following is the most commonly used semiconductor?
a) Silicon
b)
Carbon
c)
Germanium
d)
Sulphur
Answer: (a) Silicon
20. What happens to the
resistance of a pure semiconductor when heated?
a)
The resistance increases
b) The
resistance decreases
c)
The temperature remains the same
d)
Can’t say
Answer: (b) The resistance decreases
21. How many valence
electrons does a pentavalent impurity have?
a)
3
b)
4
c) 5
d)
6
Answer: (c) 5
22. How many valence
electrons do trivalent impurities have?
a)
2
b) 3
c)
4
d)
5
Answer: (b) 3
23. Which of the following
is created when trivalent impurities are added to a semiconductor?
a)
Free electrons
b) Holes
c)
Bound electrons
d)
Valence electrons
Answer: (b) Holes
24. Which of the following
does a hole in the semiconductor define?
a)
A free proton
b)
A free neutron
c)
A free-electron
d) An
incomplete part of an electron pair bond
Answer: (d) An incomplete part of an electron pair bond
25. An electron and a hole
in close proximity would tend to _____.
a) attract
each other
b)
repel each other
c)
have no effect on each other
d)
destroy each other
Answer: (a) attract each other
26. What is the random
motion of free electrons and holes due to thermal agitation called?
a)
Pressure
b) Diffusion
c)
Ionisation
d)
None of the above
Answer: (b) Diffusion
27. Why is the mobility of
free electrons greater than that of holes
a)
They are light
b)
They mutually collide less
c) They
require low energy to continue the motion
d)
They carry negative energy
Answer: (c) They require low energy to continue the motion
28. Which of the following
does the resistivity of a semiconductor depend upon?
a)
Length of the semiconductor
b) Atomic
nature of the semiconductor
c)
Shape and atomic nature of the semiconductor
d)
Shape of semiconductor
Answer: (b) Atomic nature of the semiconductor
29. Which of the following
statements is true about extrinsic semiconductors?
a)
The gap between the conduction band and the valence
bond is more than 16 eV
b) The gap
between the conduction band and the valence bond is about 1 eV
c)
The gap between the conduction band and valence band
is 100 eV and more
d)
The conduction band and the valence band overlap.
Answer: (b) The gap between the conduction band and the valence bond is
about 1 eV
29.In the left hand rule,
fore finger always represents
a)
Voltage
b)
Current
c) Magnetic
field
d)
Direction of force on the conductor
Correct Answer : (C)
30.Which of the following is
a Ferro-magnetic material?
a)
Tungsten
b)
Aluminium
c)
Copper
d) Nickel
Correct Answer : (D)
31.Ferrites are a sub-group
of
a)
Non-magnetic material
b)
Ferro-magnetic materials
c)
Paramagnetic materials
d) Ferri-magnetic
materials
Correct Answer : (D)
32.Gilbert is a unit of
a)
Electromotive force
b) Magneto
motive force
c)
Conductance
d)
Permittivity
Correct Answer : (B)
33.The working of a meter is
based on the use of a permanent magnet. In order to protect the meter
functioning from stray magnetic field
a)
Meter is surrounded by strong magnetic fields
b) A soft
iron shielding is used
c)
A plastic shielding is provided
d)
A shielding of anon-magnetic material is used
Correct Answer : (B)
34.Reciprocal of
permeability is
a) Reluctivity
b)
Susceptibility
c)
Permittivity
d)
Conductance
Correct Answer : (A)
35.The relative permeability
is less than unity in case of
a)
Ferromagnetic materials
b)
Ferrites
c)
Non-ferrous materials
d) Diamagnetic
materials
Correct Answer : (D)
36.The unit of magnetic flux
density is
a)
Weber
b)
Lumens
c) Tesla
d)
None of the above
Correct Answer : (C)
37.The magnetism left in the
iron after exciting field has been removed is known as
a)
Permeance
b) Residual
magnetism
c)
Susceptance
d)
Reluctance
Correct Answer : (B)
38.Which of the following is
not a unit of flux?
a)
Maxwell
b) Tesla
c)
Weber
d)
All of the above
Correct Answer : (B)
39.Which of the following
expected to have the maximum permeability?
a)
Brass
b)
Copper
c)
Zinc
d) Ebonite
Correct Answer : (D)
40. What is the resistivity
of a semiconductor?
a)
More than that of insulators and conductors
b) Between
that of insulators and conductors
c)
Less than that of insulators and conductors
d)
None of the above
Answer- (b).
41. Which among the
following is the most widely used semiconductor material?
a) Potassium
b) Phosphorous
c) Silicon
d) Arsenic
Answer. (c).
42. The energy gap between
the valence band and the conduction band in a semiconductor is
a) 5 eV
b) 10 eV
c) 15 eV
d) 1 eV
Answer. (d).
43. What is the sign of the
temperature coefficient of resistance in a semiconductor?
a) Negative
b) Positive
c) Zero
d) None of the above
Answer. (a).
44. How many valence
electrons are there in semiconductors?
a) 2
b) 3
c) 4
d) 6
Answer. (c).
45. What is the resistivity
of pure germanium under the standard condition?
a) 6 × 104Ω cm
b) 60 Ω cm
c) 3 ×
10-3Ω cm
d) 6 × 10-4Ω cm
Answer. (b) 60 Ω cm.
46. The resistivity of pure
silicon is
a) 100 Ω cm
b) 60,000 Ω cm
c) 3 ×
106Ω cm
d) 6 ×
10-8Ω cm
Answer. (a).100 Ω cm.
47. When a pure semiconductor
is heated, what will be the effect on its resistance?
a) Goes down
b) Goes up
c) Remains the same
d) None of the above
Answer. (a).Goes down.
48. Where does the strength of
a semiconductor crystal come from?
a) Forces between nuclei
b) Force between protons
c) Electrons-Pairs bonds
d) None of the above
Answer. (c)Electrons-Pairs bonds.
49. When a pentavalent
impurity is introduced into a pure semiconductor, it transforms into
a) Intrinsic
b) n-type
c) p-type
d) None of the above
Answer. (b).n-type.
50. What does the addition of
pentavalent impurity to semiconductors create?
a) Free Electrons
b) Holes
c) Valence electrons
d) Bound electrons
Answer. (a).Free Electrons.
51. How many valence electrons
are there in a pentavalent impurity?
a) 3 Valence electrons
b) 6 Valence electrons
c) 4 Valence electrons
d) 5 Valence electrons
Answer. (d).
52. What is the charge on a
n-type semiconductor?
a) Positively charged
b) Electrically neutral
c) Negatively charged
d) None of the above
Answer. (b).Electrically neutral.
53. How many valence electrons
are there in a trivalent impurity?
a) 3 Valence electrons
b) 5 valence electrons
c) 6 valence electrons
d) 4 valence electrons
Answer. (a).3 Valence electrons.
54. What is the other name for
a pentavalent impurity?
a) Donor impurity
b) Acceptor impurity
c) Ionic impurity
d) None of the above
Answer. (a).
55. What is the effect on the
bulk resistance on a semiconductor by adding impurities?
a) Decreases
b) Remain the same
c) Increases
d) None of the above
Answer. (a).Decreases.
56. What will happen when a
hole and electron are in close proximity?
a) Repel each other
b) Have no effect on each
other
c) Attract each other
d) None of the above
Answer. (c)
57.What is the
magneto-motive force (mmf) of a wire with 8 turns carrying three amperes of
current?
a)
2,400 AT
b)
240 AT
c) 24 AT
d)
2.4 AT
Correct Answer : (C)
58.When a magnetic is in
motion relative to a coil the induced e.m.f does not dependupon
a) resistance
of the coil
b)
Motion of the magnet
c)
Numbers of turns of coil
d)
Pole strength of the magnet
Correct Answer : (A)
59.Super magnetic materials
are composed of
a)
Ferromagnetic particles in ferromagnetic matrix
b)
Non-ferromagnetic particles in paramagnetic matrix
c) Ferromagnetic
particles in a non-ferromagnetic matrix
d)
None of the above
Correct Answer : (C)
60.When an iron piece is
placed in a magnetic field
a)
The magnetic lines of force will bend away from their
usual paths in order to go away from the piece
b) The
magnetic lines of force will bend away from their usual paths in order to go
away in order to pass through the piece
c)
The magnetic lines of force will not be affected
d)
The iron piece will break
Correct Answer : (B)
61.Fleming?s left hand rule
is used to find
a)
Direction of magnetic field due to current carrying
conductor
b)
Direction of flux in a solenoid
c) Direction
of force on a current carrying conductor in a magnetic field
d)
Polarity of magnetic pole
Correct Answer : (C)
62.The ratio of intensity of
magnetisation to the magnetisation force is known as
a)
Flux density
b) Susceptibility
c)
Relative permeability
d)
None of the above
Correct Answer : (B)
63.Magnetising steel is
normal difficult because
a)
It corrodes easily
b)
It corrodes easily
c) It has
low permeability
d)
It has high specific gravity
Correct Answer : (C)
64.The left hand rule
correlates to
a)
Current, induced e.m.f and direction of force on a
conductor
b)
Magnetic field, electric field and direction of force
on a conductor
c)
Self-induction, mutual induction and direction of
force on a conductor
d) Current,
magnetic field and direction of force on a conductor
Correct Answer : (D)
65.The unit of relative
permeability is
a)
Hennery/meter
b)
Hennery
c) It is
dimensionless
d)
Hennery/sq.m
Correct Answer : (C)
66.The force between two
long parallel conductors is inversely proportional to
a)
Radius of conductor
b)
Current in one conductor
c)
Product of current in two conductor
d) Distance between the conductors
Correct Answer : (D)
67.Material subjected to
rapid reversal of magnetism should have
a)
Large area of B-H loop
b) High
permeability and low hysteresis loss
c)
High co-ercivity and high retentivity
d)
High co-ercivity and low density
Correct Answer : (B)
3. Thermometry
and fiber optics
Q.1. In optical fiber communications, the signal
source is ________ waves.
a) Light
b)
Infrared
c)
Radio
d)
Very
low-frequency
Answer:
Light
Q.2. Which one of the following is not a guided
medium of transmission?
a)
Fiber–Optic
cable
b)
Coaxial
cable
c)
Twisted-pair
cable
d) The atmosphere
Answer: The
atmosphere
Q.3. An operating environment has many high-voltage
devices. What would be the best medium of transmission?
a)
The
atmosphere
b)
Twisted-pair
cable
c) Optical fiber
d)
Coaxial
cable
Answer:
Optical fiber
Q.4. Which of these converts the electrical signal to
optical signals?
a)
Optical
photo detectors
b)
Demultiplexers
c)
Multiplexers
d) Optical modulators
Answer: Optical
modulators
Q.5. Fiber optic system has three basic components,
in the order. They are:
a)
light
guide, light source, light detector
b) light source, light guide, light
detector
c)
light
detector, light source, light guide
d)
light
guide, light detector, light source
Answer:
light source, light guide, light detector
Q.6. In optical fiber, the outer layer is _________
and inner layer is ________________ .
a)
core,
cladding
b) cladding, core
c)
transmit,
reflect
d)
reflect,
transmit
Answer:
cladding, core
Q.7. Optical fiber cables are highly immune to EMI
because information is carried by:
a) light
b)
electrical
means
c)
magnetic
means
d)
acoustic
means
Answer:
light
Q.8. Which one of the following is based on laser
beam technology?
a)
Magnetic
tape
b)
Terminals
c) Optical disks
d)
Keyboards
Answer:
Optical disks
Q.9. _____________ method allows a large number of
selectable and independent user channels to coexist on a single optical fiber
link?
a)
PCM
b) FDM
c)
TDM
d)
CDM
Answer: FDM
Q.10. Usually various types of transmission media are
categorized as:
a)
Metallic
or nonmetallic
b) Guided or unguided
c)
Determinate
or indeterminate
d)
Fixed
or unfixed
Answer:
Guided or unguided
Q.11. _________ is a guided medium.
a)
Microwave
b)
Radio
c) Fiber-optic cable
d)
Atmosphere
Answer:
Fiber-optic cable
Q.12. Which mechanism is used in Laser Technology for
generation of light?
a)
Dispersion
b)
Absorption
c) Stimulated Emission
d)
Spontaneous
Emission
Answer:
Stimulated Emission
Q.13. Optical splice provides a connection between
a)
transmitter
to fiber
b)
receiver
to fiber
c) fiber to fiber
d)
fiber
to repeater
Answer:
fiber to fiber
Q.14. Optical fibers are highly immune to EMI. Which
one of the following four statements justifies it?
a) They transmit signals in as light
rather than electric current.
b)
They
are readily shielded by outer conductors in cable.
c)
They
are too small for magnetic fields to introduce current in them.
d)
Magnetic
fields cannot penetrate the glass of the fiber.
Answer: They
transmit signals in as light rather than electric current.
Q.15. In an optical fiber, the fiber core
____________ the cladding.
a) is denser than
b)
has
the same density as
c)
is
less dense than
d)
is
another name for
Answer: is
denser than
Q.16. The material used for fabrication of inner core
of an optical fiber is
a) glass or plastic
b)
bimetallic
c)
copper
d)
liquid
Answer:
glass or plastic
Q.17. Unlike wired media, optical fibers are highly
resistant to
a)
refraction
b)
low-frequency
transmission
c) electromagnetic interference
d)
high-frequency
transmission
Answer:
electromagnetic interference
Q.18. The light is propagated within the fiber core
by the phenomenon
a)
total
internal reflection at core-cladding intersection
b)
refraction
at core-cladding intersection
c) total internal reflection at the
outer surface of the cladding
d)
change
in the velocity of light within the fiber core
Answer:
total internal reflection at core-cladding intersection
19. Measurement of elevated temperatures is defined
as ___________
a) Thermometry
b) Pyrometry
c) Metallography
d) Radiography
Answer: b
20. What temperature does the dark red color
generally deal with?
a) 950 F
b) 1150 F
c) 1175 F
d) 1300 F
Answer: b
21. What temperature is the dark orange color
associated with?
a) 1475 F
b) 1650 F
c) 1750 F
d) 1800 F
Answer: b
22. Bimetallic strips are employed in ________
thermometers.
a) Vapor-pressure
b) Liquid-expansion
c) Metal-expansion
d) Resistance
Answer: c
23. Bimetallic strips contain _______ as a metal.
a) Muntz metal
b) Yellow brass
c) Bronze
d) Aluminum
Answer: b
24. Why is invar used in bimetallic strips?
a) Low density
b) Low coefficient of expansion
c) High-temperature resistance
d) High abrasion resistance
Answer: b
25. _______ is commonly used in liquid-expansion
thermometers.
a) Bourdon tube
b) Spinning rotor gauge
c) McLeod gauge
d) Manometer
Answer: a
26. Resistance thermometer generally makes use of
________ for the measurement of resistance.
a) Potentiometer
b) Adruino
c) Diode bridge
d) Wheatstone bridge
Answer: d
27. Which of these materials is not used for
resistance coils?
a) Nickel
b) Copper
c) Titanium
d) Platinum
View Answer
Answer: c
28. Liquid expansion thermometers are filled with
________
a) Mercury
b) Amalgam
c) Gallium
d) Cesium
View Answer
Answer: a
29. A step-index fiber has specified parameters for
refractive index of fiber core and cladding as 1.50 and 1.46, respectively. Its
numerical aperture is
a) 0.344
b)
0.156
c)
0.486
d)
0.244
Answer:
0.344
30. A step-index fiber has specified parameters for refractive
index of fiber core and cladding as 1.50 and 1.33, respectively. Its acceptance
angle will be approximately
a)
25°
b)
20°
c) 15°
d)
10°
Answer: 15°
31. Consider a ray of light propagating from one
medium to another medium having different indexes of refraction. If the
incidence angle is greater than the specified critical angle, then _______ occurs.
a) reflection
b)
refraction
c)
diffraction
d)
scattering
Answer:
reflection
32. When the incidence angle is ___________ the
specified critical angle, the light rays bend along the intersection line of
two different mediums of propagation.
a)
more
than
b)
less
than
c) equal to
d)
not
related with
Answer:
equal to
33. In ____________ profile optical fibers, the
propagation of light rays is almost horizontal provided the low-refractive
index fiber core has relatively smaller diameter as compared with those of
other types of optical fibers.
a)
multimode
step-index
b)
multimode
graded-index
c)
multimode
single-index
d) single-mode
Answer:
single-mode
34. Dispersion (i.e., distortion in the transmitted
optical pulse) is maximum in _________ type of optical fibers.
a) Multimode step-index
b)
Multimode
graded-index
c)
Multimode
single-index
d)
Single-mode
Answer:
Multimode step-index
35. In __________ type of optical fiber cables, the
density of the fiber core varies.
a)
multimode
step-index
b) multimode graded-index
c)
multimode
single-index
d)
single-mode
Answer:
multimode graded-index
36. In optical fibers, the index of refraction in the
fiber core is always
a) greater than that of cladding
b)
less
than that of cladding
c)
equal
to that of cladding
d)
not
at all related with that of cladding
Answer:
greater than that of cladding
37. For single-mode step index fibers, V-number
should be less than
a) 2.4
b)
2.8
c)
4.2
d)
8
Answer: 2.4
38. Which one of the following types does not exist
in optical fibers?
a)
single-mode
step-index
b) single-mode graded-index
c)
multimode
step-index
d)
multimode
graded-index
Answer:
single-mode graded-index
39. The essential condition for total internal
reflection to take place within the optical fiber is when the incidence angle
exceeds the specified value of
a) critical angle
b)
refraction
angle
c)
reflection
angle
d)
acceptance
angle
Answer:
critical angle
40. The rays which do not intersect the core axis are
called
a)
meridional
rays
b)
radial
rays
c)
helical
rays
d) skew rays
Answer: skew
rays
41. Measurement of elevated temperatures is defined
as ___________
a) Thermometry
b) Pyrometry
c) Metallography
d) Radiography
Answer: b
42. What temperature does the dark red color
generally deal with?
a) 950 F
b) 1150 F
c) 1175 F
d) 1300 F
Answer: b
43. What temperature is the dark orange color
associated with?
a) 1475 F
b) 1650 F
c) 1750 F
d) 1800 F
Answer: b
44. Bimetallic strips are employed in ________
thermometers.
a) Vapor-pressure
b) Liquid-expansion
c) Metal-expansion
d) Resistance
Answer: c
45. Bimetallic strips contain _______ as a metal.
a) Muntz metal
b) Yellow brass
c) Bronze
d) Aluminum
Answer: b
46. Why is invar used in bimetallic strips?
a) Low density
b) Low coefficient of expansion
c) High-temperature resistance
d) High abrasion resistance
Answer: b
47. _______ is commonly used in liquid-expansion
thermometers.
a) Bourdon tube
b) Spinning rotor gauge
c) McLeod gauge
d) Manometer
Answer: a
48. Resistance thermometer generally makes use of ________
for the measurement of resistance.
a) Potentiometer
b) Adruino
c) Diode bridge
d) Wheatstone bridge
Answer: d
49. Which of these materials is not used for
resistance coils?
a) Nickel
b) Copper
c) Titanium
d) Platinum
Answer: c
50. Liquid expansion thermometers are filled with
________
a) Mercury
b) Amalgam
c) Gallium
d) Cesium
Answer: a