Friday, May 20, 2022


1.The temperature, under thermal and electrical
system analogy, is considered analogous to
(a) voltage
(b) current
(c) capacitance
(d) charge
(e) none of the above
Ans: a
2.In electrical-pneumatic system analogy the current
is considered analogous to
(a) velocity
(b) pressure
(c) air flow
(d) air flow rate
Ans: d
3.In liquid level and electrical system analogy,
voltage is considered analogous to
(a) head
(b) liquid flow
(c) liquid flow rate
(d) none of the above
Ans: a
4.The viscous friction co-efficient, in force-voltage
analogy, is analogous to
(a) charge
(b) resistance
(c) reciprocal of inductance
(d) reciprocal of conductance
(e) none of the above
Ans: b
5.In force-voltage analogy, velocity is analogous to
(a) current
(b) charge
(c) inductance
(d) capacitance
Ans: a
6.In thermal-electrical analogy charge is considered
analogous to
(a) heat flow
(b) reciprocal of heat flow
(c) reciprocal of temperature
(d) temperature
(e) none of the above
Ans: d
7.Mass, in force-voltage analogy, is analogous to
(a) charge
(b) current
(c) inductance
(d) resistance
Ans: c
8.In a stable control system backlash can cause which
of the following ?
(a) Underdamping
(b) Overdamping
(c) Poor stability at reduced values of open loop gain
(d) Low-level oscillations
Ans: d
9.In an automatic control system which of the
following elements is not used ?
(a) Error detector
(b) Final control element
(c) Sensor
(d) Oscillator
Ans: d
10.In a control system the output of the controller is
given to
(a) final control element
(b) amplifier
(c) comparator
(d) sensor
(e) none of the above
Ans: a
11.A controller, essentially, is a
(a) sensor
(b) clipper
(c) comparator
(d) amplifier
Ans: c
12.The capacitance, in force-current analogy, is analogous to
(a) momentum
(b) velocity
(c) displacement
(d) mass
Ans: d
13.Which of the following devices are commonly used as
error detectors in instruments ?
(a) Vernistats
(b) Microsyns
(c) Resolvers
(d) Any of the above
Ans: d
14.Which of the following should be done to make an
unstable system stable ?
(a) The gain of the system should be decreased
(b) The gain of the system should be increased
(c) The number of poles to the loop transfer function should be increased
(d) The number of zeros to the loop transfer function should be
Ans: b
15.increases the steady state accuracy.
(a) Integrator
(b) Differentiator
(c) Phase lead compensator
(d) Phase lag compensator
Ans: a
16.A.C. servomotor resembles
(a) two phase induction motor
(b) Three phase induction motor
(c) direct current series motor
(d) universal motor
Ans: a
17.As a result of introduction of negative feedback
which of the following will not decrease ?
(a) Band width
(b) Overall gain
(c) Distortion
(d) Instability
Ans: a
18.Regenerative feedback implies feedback with
(a) oscillations
(b) step input
(c) negative sign
(d) positive sign
Ans: d
19.The output of a feedback control system must be a
function of
(a) reference and output
(b) reference and input
(e) input and feedback signal
(d) output and feedback signal
Ans: a an open loop control system.
(a) Ward Leonard control
(b) Field controlled D.C. motor
(c) Stroboscope
(d) Metadyne
Ans: b
21.A control system with excessive noise, is likely to
suffer from
(a) saturation in amplifying stages
(b) loss of gain
(c) vibrations
(d) oscillations
Ans: a
22.Zero initial condition for a system means
(a) input reference signal is zero
(b) zero stored energy
(c) ne initial movement of moving parts
(d) system is at rest and no energy is stored in any of its
Ans: d
23.Transfer function of a system is used to calculate
which of the following ?
(a) The order of the system
(b) The time constant
(c) The output for any given input
(d) The steady state gain
Ans: c
24.The band width, in a feedback amplifier.
(a) remains unaffected
(b) decreases by the same amount as the gain increase
(c) increases by the sane saaaajajt as the gain decrease
(d) decreases by the same amount as the gain decrease
Ans: c
25.On which of the following factors does the
sensitivity of a closed loop system to gain changes and
load disturbances depend ?
(a) Frequency
(b) Loop gain
(c) Forward gain
(d) All of the above
Ans: d
26.The transient response, with feedback system,
(a) rises slowly
(b) rises quickly
(c) decays slowly
(d) decays quickly
Ans: d
27.The second derivative input signals modify which of
the following ?
(a) The time constant of the system
(b) Damping of the system
(c) The gain of the system
(d) The time constant and suppress the oscillations
(e) None of the above
Ans: d
28.Which of the following statements is correct for
any closed loop system ?
(a) All the co-efficients can have zero value
(6) All the co-efficients are always non-zero
(c) Only one of the static error co-efficients has a finite
non-zero value
(d) None of the above
Ans: c
29.Which of the following statements is correct for a
system with gain margin close to unity or a phase margin close to zero ?
(a) The system is relatively stable
(b) The system is highly stable
(c) The system is highly oscillatory
(d) None of the above
Ans: c
30.Due to which of the following reasons excessive
bond width in control systems should be avoided ?
(a) It leads to slow speed of response
(b) It leads to low relative stability
(c) Noise is proportional to band width
(d) None of the above
Ans: c
31. Which is the lightest particle of an atom?
(a) Neutron
(b) Electron
(c) Proton
(d) All
Answer: Electron
32. Ampere second could be the unit of –
(a) Power
(b) Conductance.
(c) Energy
(d) Charge
Answer: Charge
33.The ratio of resistance of a 100W, 220V lamp to
that of 100W lamp will be nearly-
(a) 4
(b) 8
(c) 1/4
(d) 1/2
Answer: 4
34.If the length and cross section of piece of
conductor are both doubted what be its resistance(initial resistance R)?
(a) 4R
(b) 2R
(c) R
(d) 0.25R
Answer: 4R
35. The number of electron in the outermost orbit of
carbon atom is ?
(a) 8
(b) 2
(c) 4
(d) 6
Answer: 4
36. Which one of the following semi-conductor ?
(a) Copper
(b) Silicon
(c) Neon
(d) Lithium
Answer: Silicon
37. For an R-L load-
(a) Active Power is better than apparent power
(b) Reactive Power is better than apparent power
(c) Apparent power is better than both active and reactive power
(d) All the equal
Answer: Apparent power is better than both active and reactive power
38.One Horse power is equal to –
(a) 5.50 foot pound/ second
(b) 55.00 foot pound/ second
(c) 550 foot pound/second
(d) 5550 foot pound/second
Answer: 550 foot pound/second
39. Satellite power requirement is provided through

(a) Lead-acid batteries
(b) Dry cell
(c) Solar cells
(d) Nickel cadmium cell
Answer: Solar Cells
40.A radio station broadcast at 30m wavelength.The
frequency of broadcast wiil be-
(a) 30Hz
(b) 300Hz
(c) 10MHz
(d) 10KHz
Answer: 10MHz
41.A short circuit test on transformer oil is-
(a) Copper loss at full load
(b) Copper loss at half load
(c) Iron loss at any load
(d) Sum of iron losses and copper losses
Answer: Copper loss at full load.
42.The type of oil which is suitable as transformer
oil is-
(a) Animal oil
(b) Cooking oil
(c) Mineral oil
(d) Vegetable oil
Answer: Mineral Oil
43. Bucholz relay used on-
(a) Air cooled transformer.
(b) Oil cooled transformers.
(c) Welding transformers.
(d) Furnace transformer.
Answer: Oil cooled transformers.
44. Burden of current transformer is usually
expressed in-
(a) Volts
(b) Amperes
(c) Volt amperes
(d) Kilowatt
Answer: Amperes
45. Which distribution system is more reliable?
(a) Ring main system
(b) Tree system
(c) Radial system
(d) All are equally reliable.
Answer: Ring main system.
46.Common declared distribution voltage in
Bangladesh for low voltage circuit is –
(a) 230 Volt
(b) 440 Volt
(c) 250 Volt
(d)350 Volt
Answer: 230 Volt
47. The phenomena of creeping occurs in-
(a) Ammeter
(b) Voltmeter
(c) Wattmeter
(d) Watt-hour meter
Answer: Watt-hour meter
48.The unit of resistivity is
(a) Ohms
(b) Ohm-m
(c) Ohm/sqm
(d) None
Answer: Ohm-m
49. Three equal resistors of hundred ohm is
connected in series across a source of E.m.f 30V.What would be the power
consumed by is resistor?
(a) 10 W
(b) 30 W
(c) 90 W
(d) 60 W
Answer:10 W
50.What would be the charge of a uF when connected
with 20V supply?
(a) 2000 uC
(b) 200 uC
(c) 300 uC
(d) 30 uC
Answer: 200 uC
51.Which power factor is more economical for the
(a) 0.85 Lagging
(b) 0.95 Lagging
(c) 0.10 Leading
(d) 0.85 Leading
Answer: 0.95 Lagging.
52. One Cubic water is equal to-
(a) 74.6 U.S Gallon
(b) 628 pound water
(c) 28.375 Line
(d) 28.3 Cubic meter
Answer: 28.3 Cubic meter
53. Active power is equal to-
(a) F Z
(b)VI Sin
(c)VI Cos
(d) None
Answer: VI Cos
54.Which is the used power factor improvement-
(a) Spring motor
(b) Commutator motor
(c) Synchronous motor
(d) Squirrel Case Motor
Answer: Synchronous motor.
55.If the power factor of a circuit is unity, its
reactive power is-
(a) A maximum
(b) Equal to FR
(c) Zero
(d) A negative quantity
Answer: Zero
56.How can eddy current loss be minimized ?
(a)By using copper core
(b) By using solid core
(c) By laminating the core
(d) None of above
Answer: By laminating the core.
57.Dose the transformer draw any current when its
secondary is open ?
(a) No
(b) Yes
(c) Take rated current
(d) None
Answer: Yes
58.A transformer has negative voltage regulation
when its load power factor is-
(a) Zero
(b) Unity
(c) Leading
(d) Lagging
Answer: Leading
59. Permanent magnet is normally made of-
(a) Aluminum
(b) Wrought iron
(c) Cast iron
(d) Alnico alloys
Answer: Cast Iron
60. A carbon resistor contains
(a) carbon crystals
(b) solid carbon granules
(c) pulverized coal
(d) finely divided carbon black.
Ans: d
61. Which of the following materials does not have
covalent bonds ?
(a) Organic polymers
(b) Silicon
(c) Metals
Ans: c
62. In graphite, bonding is
(a) covalent
(b) metallic
(c) Vander Waals
(d) Vander Waals and covalent
Ans: d
63. Total number of crystal systems is
(a) 2
(b) 4
(c) 7
(d) 12
Ans: c
64. The number of atoms per unit cell in B.C.C.
structure is
(a) 1
(b) 2
(c) 4
(d) 8
Ans: b
65. The conductivity of a metal is determined by
(a) the electronic concentration and the mobility of the free electrons
(6) the number of valence electrons per atom
(c) either (a) or (b)
(d) none of the above
Ans: a
66. The resistivity of a metal is a function of
temperature because
(a) the amplitude of vibration of the atoms varies with temperature
(b) the electron density varies with temperature
(c) the electron gas density varies with temperature
Ans: a
67. In a crystal, an atom vibrates at a frequency
determined by
(a) the heat content of the crystal
(b) the temperature of the crystal
(c) the stiffness of the bonds it makes with neighbors
Ans: c
68. Due to which of the following reasons aluminium
does not corrode in atmosphere ?
(a) Aluminium is a noble metal
(b) Atmospheric oxygen can only diffuse very slowly through the oxide layer
which is formed on the surface of aluminium
(c) No reaction with oxygen occurs ft Any of the above
Ans: b
69. The impurity atoms is semiconductors
(a) inject more charge carriers
(6) reduce the energy gap
(c) increase the kinetic energy of valence electrons
(d) all of the above
Ans: b
70. Which of the following material is not a
semiconductor ?
(a) Silica
(b) Germanium
(c) Selenium
(d) Gallium-arsenide
Ans: a
71. Carbon resistors are used extensively because
they are
(a) easy to make
(b) compact
(c) inexpensive
(d) all of the above reasons
Ans: d
72. Carbon rods are used in wet and dry cells
(a) carbon rod serves as conductor
(b) carbon can resist the attack of battery acid
(c) both (a) and (b)
(d) either (a) or (b)
Ans: c
73. Due to which of the following factors the brush
wear rate is altered ?
(a) Speed of the machine
(b) Contact pressure
(c) Surface conditions of brush and commutator
(d) Excessive sparking
(e) All of the above
Ans: e
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