BASIC ELECTRICAL MOST ASKED OBJECTIVE QUESTIONS & ANSWER PDF FOR VIZAG MT EXAM 2017

BASIC ELECTRICAL MOST ASKED

BASIC ELECTRICAL MOST ASKED

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Attempt Free BASIC ELECTRICAL MOST ASKED Here. Read The Important Electrical MCQ From Below.

1.  Basic source of magnetism                               .
(a) Charged particles alone
(b) Movement of charged particles

(c) Magnetic dipoles
(d) Magnetic domains
Answer-B
2.  Units for magnetic flux density
(a) Wb / m2
(b) Wb / A.m
(c) A / m
(d) Tesla / m
Answer-A
3.  Magnetic permeability has units as
(a) Wb / m2
(b) Wb / A.m
(c) A / m
(d) Tesla / m
Answer-B
BASIC ELECTRICAL MOST ASKED
4.  Magnetic permeability has units as
(a) Tesla
(b) Henry
(c) Tesla / m
(d) Henry / m
Answer-D
5.  Magnetic field strength’s units are
(a) Wb / m2
(b) Wb / A.m
(c) A / m
(d) Tesla / m
Answer-C
6.  Example for dia-magnetic materials
(a) super conductors
(b) alkali metals
(c) transition metals
(d) Ferrites
Answer-A
BASIC ELECTRICAL MOST ASKED
7.  Example for para-magnetic materials
(a) super conductors
(b) alkali metals
(c) transition metals
(d) Ferrites
Answer-B
8.  Example for ferro-magnetic materials
(a) super conductors
(b) alkali metals
(c) transition metals
(d) Ferrites
Answer-C
9.  Example for anti-ferro-magnetic materials
(a) salts of transition elements
(b) rare earth elements
(c) transition metals
(d) Ferrites
Answer-A
10.  Example for ferri-magnetic materials
(a) salts of transition elements
(b) rare earth elements
(c) transition metals
(d) Ferrite
Answer-D
BASIC ELECTRICAL MOST ASKED
11.Which of following circuit element stores energy in electromagnetic field?
(a)inductor
(b)condenser
(c)variable resistor
(d)capacitor
Answer-A
12.Emf induced in a coil rotating in a uniform magnetic field will be maximum when the
(a)flux linking with the coil is maximum
(b) rate of change of flux linkage is minimum.
(c) rate of change of flux linkage is maximum.
(d) rate of cutting flux by coil sides is minimum.
Answer-C
13.The emf induced in a conductor rotating in bipolar field is
 (a)dc
(b)ac
(c)dc and ac both
(d)none of these
Answer-B
14.The direction of induced emf can be found by
(a)kirchoffs law
(b)lenz law
(c)Flemings righthandrule
(d)laplace law
Answer-C
BASIC ELECTRICAL MOST ASKED
15.A coil with negligible resistance has 50 V across it with 10 mA. The inductive reactance is
(a)50ohms
(b)500ohms
(c)1000ohms
(d)5000ohms
Answer-D
16.A copper disc is rotated rapidly below a freely suspended magnetic needle. The magnetic needle starts rotating with velocity
(a) equal to that of disc and in the same direction.
(b) equal to that of disc and in the opposite direction.
(c) less than that of disc and in the same direction.
(d) less than that of disc but in opposite direction.
Answer-C
17.The working principle of transformer depend son
(a) Coulomb’s law.
(b) Faraday’s law of electromagnetic induction.
(c) Ampere’s law.
(d) Newton’s law
Answer-B
BASIC ELECTRICAL MOST ASKED
18.Maxwell is the same as
(a) 10-8 weber
(b) 108 weber.
(c) 104 weber.
(d) 10-4  weber.
Answer-A
19.  When a magnet is in motion relative to a coil the induced emf does not depend upon
(a) pole strength of the magnet
(b) motion of the magnet.
(c) resistance of the coil.
(d) number of turns of the coil
Answer-C
20.Self inductance of magnetic coil is proportional to
(a)N
(B)1/N
(c) N2.
(d)1/ N2.
Answer-C
BASIC ELECTRICAL MOST ASKED
21.A coil is wound on iron core which carries current I. The self-induced voltage in the coil is not affected by
(a) variation in coil current.
(b) variation in voltage to the coil.
(c) change the number of turns of coil.
(d) the resistance of magnetic path.
Answer-C
22.  Both the number of turns and the core length of an inductive coil are doubled. Its self-inductance will be
a)unaffected.
(b) doubled.
(c) halved.
(d)quadrupled
Answer-B
23.The magnitude of the induced emf in a conductor depends upon on the
(a) flux density of the magnetic field.
(b) amount of flux cut.
(c) amount of flux linkage.
(d) rate of change of flux linkage.
Answer-B
BASIC ELECTRICAL MOST ASKED
24.  The property of the coil by which a counter emf is induced in it when the current through the coil changes is known as
(a) self inductance.
(b) mutual inductance.
(c) series aiding inductance.
(d) capacitance.
Answer-A
25.In case of all flux from the current in coil 1 links with coil 2, the coefficient of coupling will be
(a)2.0
(b)1.0
(c)0.5
(d)zero
Answers-B
26.  Even though an ac waveform can take any shape theis the most preferable.
A.   Square wave
B. Sine wave
C. Triangular wave
D. Rectified wave
Answer-A
BASIC ELECTRICAL MOST ASKED
27.  The period of a wave is
A.   The same as frequency
B. Time required to complete one cycle
C. Express in amperes
D. None of the above
Answer-B
28.  The form factor is the ratio of
A.   Peak value to the rms value
B. RMS value to average value
C. Average value to rms value
D. None of the above
Answer-B
29.  The period of a sine wave is 1/50seconds. Its frequency is .
A.    20 Hz
B. 30 Hz
C. 40 Hz
D. 50 Hz
Answer-D
30.  Power factor of the following circuit will be unity
A.  Inductive
B. Capacitive
C. Resistive
D. Both A and B
Answer-C
31.  The maximum value of an ac quantity is called as its
A.    Amplitude
B. Peak to peak value
C. RMS value
D. None of above
Answer-B
BASIC ELECTRICAL MOST ASKED
32.  The capacitive reactance is defined as XC
A.    2πfc
B. 1/2πfc
C. Wc
D. 2πfl
Answer-B
33.  If voltage across pure resistance is V=Vmsin(wt+π/6) then current flowing through it will be I=           A.    IMsin(wt)
B. IMsin(wt+π /6)
C. IMsin(wt-π/6)
D. IMsin(wt+π/2)
Answer-B
34.  Average power is purely resistive ac circuit is equal to P=
A.    VIsin Ф
B. VIcos Ф
C. VI
D. VMIM
Answer- C
35.  The can never store energy.
A.    Resistor
B. Inductor
C. Capacitor
D. Energy source
Answer-D
36.  For a purely inductive ac circuit theleadsby 90º
A.    Current, voltage
B. Voltage, current
C. Power, current
D. Voltage, power
Answer-B
BASIC ELECTRICAL MOST ASKED
37.  The is directly proportional to frequency.
A.    Capacitive reactance
B. Hysteresis loss
C. Inductive reactance
D. Eddy current loss
Answer-C
38.  For RL series circuit the current the applied voltage by
A.    Leads, 0 to 90º
B. Lags, 0 to 90º
C. Leads, 90º
D. Lags,90º
Answer-B
39.  The impedance of RC series circuit is given by Z=
A.    R+jXC
B. R-jXC
C. R×jXC
D. None of above
Answer-A
40.  The average power consumed by a pure capacitor is .
A.    VIsinΦ
B. VI
C. VIcosФ
D. 0
Answer-D
41.  The RLC series circuit isif XL=XC.
A.    Inductive
B. Capacitive
C. Resistive
D. None of above
Answer-C
BASIC ELECTRICAL MOST ASKED
42.  The Q-factor can be defined as Q=at f=fr.
A.    XL×R
B. XC× R
C. XL/R
D. XL+R
Answer-C
43.  If R = 3Ω is in series with XL=4Ω. Then the admittance of this circuit is Y= s.
A. 5
B. 25
C. 0.2
D. 0.04
Answer-D
44.  The reactive power is also called aspower and it expressed in .
A.    True, VAR
B. Imaginary, VAR
C. Imaginary, VA
D. Real , VA
Answer-B
BASIC ELECTRICAL MOST ASKED
45.  All the home appliances operates onVoltage.
A.    AC
B. DC
C. AC or DC
D. None of the above
Answer-A
46.  In the equation V(t) = Vm × Sin(wt), V(t) indicates theValue.
A.    RMS
B. Peak
C. Instantaneous
D. Average
Answer-C
47.  The instantaneous value of voltage at t=t1 is given by,
A.    V(t=t1)
B. V(t1)
C. V/t1
D. None of these
Answer-A
BASIC ELECTRICAL MOST ASKED
48.1 Cycle =
A. π radian
B. 2π radian
C. 4π radian
D. 1800
Answer-B
49.  The frequency of the AC mains is
A.    50 Hz
B. 25 Hz
C. 100 Hz
D. 50 sec.
Answer-A
50.  The frequency of the AC quantity is measured in.
A.    units/sec
B. cycles-sec
C. cycles/sec
D. Sec/cycles
Answer-C
51.  Thevalue is also called Amplitude.
A.   RMS
B. Peak
C. Average
D. Instantaneous
Answer-B
BASIC ELECTRICAL MOST ASKED
52.  Thevalue of the sine wave is 0.707Vm.
A.  Average
B. Peak
C. RMS
D. Instantaneous
Answer-B
53.  The average value of the sinusoidal voltage waveform is.
A 0.637 Irms
B. 0.707 Irms
C. 0.637 Imax
D. 0.707 Imax
Answer-C
54.  The AC voltmeter or ammeter measures thevalue.
A.   Average
B. RMS
C. Peak
D. Instantaneous
Answer-B
BASIC ELECTRICAL MOST ASKED
55.  The average value of a symmetrical AC waveform is determined from the ─ of the waveform.
A.    Full cycle
B. Half Cycle
C. Full or Half Cycle
D. None of these
Answer-B
56.  The value of the form factor for the sinusoidal waveform is.
A. 0.909
B. 0.637
C. 0.707
D. 1.11
Answer-D
57.  The value of peak factor for a sinusoidal waveform is.
A. 1
B. 0.707
C. 1.414
D. 0.637
Answer-C
58.  The correct expression for the form factor is K
A.    Imax/Iavg
B. Irms/Iavg
C. Imax/Iavg
D. Ip-p/Irms
Answer-B
BASIC ELECTRICAL MOST ASKED
59.  The length of the phasor represents theof the sinusoidal quantity.
A.    Amplitude
B. Average value
C. RMS value
D. Instantaneous value
Answer-A
60.  Form factor is always.
A.    Greater than 1
B. Less than 1
C. Equal to 1
D. zero
Answer-A
61.  Complete the following formula, 1 rad =degree.
A. π/180
B. 180/π
C. π/360
D. 360/π
Answer-A
62.  The phasor rotates indirection.
A.    Clockwise
B. Anti Clockwise
C. Random
D. None of these
Answer-B
BASIC ELECTRICAL MOST ASKED
63.  The projection of phasor on Y axis isvalue.
A.   Peak
B. Instantaneous
C. Average
D. RMS
Answer-B

64.  The phase angles can take any value between _and

A. 0, 2π

B. 0, π

C. 0, 1800

D. π, 2π

Answer-A
65.  For the expression V(t)=100sin(100wt+π/4), the phase difference is,
A.   π/4 lagging
B. π/4 leading
C. 100π leading
D. 100π lagging
Answer-B
66.  A sinusoidal current has peak factor 1.4 and form factor 1. If average value of current is 20A, then RMS value of current isA and peak value is
A. 22, 30.8
B. 30.8, 22
C. 18.18, 25.7
D. 18, 25
Answer-A
BASIC ELECTRICAL MOST ASKED
67.  Thebetween two phasors represents the phase difference between two quantities.
A.    Length difference
B. Speed difference
C. Angle Difference
D. None of these
Answer-C
68.  The phasor represented in rectangular form as i=(20-j34.64)A in its equivalent polar form as,
A. 40<-600A
B. 40<600A
C. 54.54<600A
D. None of these
Answer-A
69.  An alternating current is given by I = 14.14sin(377t). What is the RMS value?
A. 14.14A
B. 10 A
C. 377 A
D. 9 A
Answer-B
BASIC ELECTRICAL MOST ASKED
70.  An alternating current is given by I = 14.14 sin (377t), its time period is.
A.    20 msec
B. 16.67 msec
C. 2.65 msec
D. 5.3 msec
Answer-B
71.  The AC voltage generator is called as.
A.    Alternator
B. Induction Generators
C. Alternating Generator
D. None of these
Answer-A
72.  Thevalue of AC quantity is defined as the value of that quantity at a particular instant of time.
A.    DC
B. AC
C. Instantaneous
D. RMS
Answer-C
73.  An AC quantity (Voltage, Current or Power) is defined as the one which changes its as well as with respect to time.
A. Value, direction
B. Phase, polarity
C. Value, phase
D. None of these
Answer-A
BASIC ELECTRICAL MOST ASKED

74.The repetition consisting of one positive and one identical negative part is called as the of the waveform.

A. Time period

B. One cycle

C. Frequency

D. None of these

Answer-B
75.  Peak to peak values are most often used when measuring the magnitude on the
 A.    Voltmeter
B. Cathode ray oscilloscope
C. Digital multimeter
D. None of these
Answer-B
76.  What is the phase angle of a series RLC circuit at Resonance
a)INFINITY
b) zero
c)  45 deg
d)  90 deg lag
Answer-B
BASIC ELECTRICAL MOST ASKED
77.  What is the total reactance of a series RLC circuit at Resonance
a)    Zero
b) equal to XL
c) equal to Xc
d) R
Answer-A
78.  The magnitude & phase of current vector is depend on the values of
a)   R
d) L
c) C and f
d) all of the above
Answer-D
79.  If the Band width is low the selectivity will be
a) High
b) Low
c) zero
d) none
Answer-A
80.Resonance is defined as
a)  in a circuit angle between voltage and current is Ø
b)  in a circuit angle between voltage and current is zero
c)  in a circuit angle between voltage and current is unity
d)  none
Answer-B
BASIC ELECTRICAL MOST ASKED
81. At resonance , in RLC series circuit   , the circuit behaves as
a) Inductive ciruit
b) capacitive circuit
c) resistive circuit
d) none
Answer-C
82. At frequency less than resonace frequency   in RLC series circuit, the circuit behaves as
a) Inductive ciruit
b) capacitive circuit
c) resistive circuit
d) none
Answer-B
83.  At frequency greater than resonace frequency in RLC series circuit, the circuit behaves as
a) Inductive ciruit
b) capacitive circuit
c) resistive circuit  d) none
Answer-A
84.Resonance frequency equation
a)  1/LC
b) 1/(LC)1/2
C) 1/C
D) None
Answer-B
BASIC ELECTRICAL MOST ASKED
85.   At Resonance in RLC series circuit,  Current in circuit is
a) Minimum
b) Maximum
c) can’t say
d) none
Answer-B
86.  At Resonance in RLC series circuit, Impedane is
a) Minimum
b) Maximum
c) can’t say
d) none
Answer-A
87.  At Resonance in RLC series circuit, Admittance is
a) Minimum
b) Maximum
c) can’t say
d) none
Answer-B
BASIC ELECTRICAL MOST ASKED
88.  At Resonance in RLC parallel circuit,  voltage  in circuit is
a) Minimum
b) Maximum
c) can’t say
d) none
 Answer-B
89. At Resonance in RLC parallel circuit,
a) Minimum
b) Maximum
c) can’t say impedance  in circuit is
d) none
Answer-B
90. At Resonance in RLC parallel circuit, admittance  in circuit is
a)    Minimum
b) Maximum
c) can’t say
d) none
Answer-A
91. Resonance frequency in RLC parallel circuit
a) 1/2π(LC)1/2
b) 1/(LC)1/2
c)Zero

Answer-A

BASIC ELECTRICAL MOST ASKED

92.   Quality Factor can be defined as
a) Maximum stored energy
b) energy dissipated per cycle
c) 2π(Maximum stored energy)/(Energy dissipated per cycle )
d) None
Answer-C
93.   In series RLC circuit , at resonance
a) Z= R
b) Z= 1/R
c)   R/2
d) 2/R
Answer-A
94.  Q is equal to
a) w0L/R
b) 1/W0RC
c) Zero
d)both a and b
Answer-D
95.Bandwidth is euqal to
a) Q0/f0
b) f0/Q0
c) 0
d) none
Answer-B
BASIC ELECTRICAL MOST ASKED
96.  Energy dissipated per cyclin the circuit in RLC series is
a)   Product of the average power in the resistor  and the time period
b)   Product of voltage and current
c)  product of voltage and power
d) None.
Answer-A
97.In series RLC circuit R= 10 ohms and L= 5mH and C= 12.5 micro F. calculate angular frequency
a)      400 rad/s
b) 4000 rad/s
c) 40 rad/s
d) 40000 rad/s
Answer-B
98.In series RLC circuit R= 10 ohms and L= 5mH and C= 12.5 micro F. calculate Z0  is equal to
a)   10 ohms
b) -10 ohms
c) 1/10 ohms
d) -1/10 ohms
Answer-A
99.  A series circuit R = 5 ohms and L= 20 mH and variable capacitance C has an applied voltage with a frequency f = 1000 Hz. Find C for series resonance.
a) 1.27 micro F
b) 1.37 micro F
c) 0.4 micro F
d) None.
Answer-A
BASIC ELECTRICAL MOST ASKED
100.W0 =
a) W1
b) W2
c) (W1W2)1/2
d) None
Answer -C
101. Bandwidth is defined as the range of frequencies within which the power delivered to R is
a) equal to half power at resonance
b) less than half  the power at resonance
c) greater than half power at resonance
d) None.
Answer-C
102 . When a pure Lc parallel circuit is in resonance, the circuit condition can be represented by
a) Short circuit
b) open circuit
c) a normal parallel circuit
d) None of these
Answer-B
103. Which of the condition is common to both series and parallel resonance
a) Impedance is minimum
b) power factor  unity
c) power is low
d) Q factor depends on voltage amplification
Answer-B
BASIC ELECTRICAL MOST ASKED
104.The  Q factor of a circuit is defined as
a) reactive power/resistive
b) w0L/R
c) both  a and b
d) None
Answer-B
105.   In an RLC series circuit, which of the following are correct when the frequency of the source is varied from zero to infinity
a)  inductive reactance is less than capacitive reactance
b)  capacitive reactance is less thant inductive reactance
c)  inductive reactance is equal to  cpapacitive reactance
d)  all of these
Answer-D
106.In series RLC circuit, resonance occurs when
a) L= C
b) R= C
c) R= L
d) inductive reactance is capacitive reactance
Answer-D
107.  If R = 3Ω is in series with XL=4Ω. Then the admittance of this circuit is Y=
A. 5
B. 25
C. 0.2
D. 0.04
Answer-D
BASIC ELECTRICAL MOST ASKED
108.  The parallel resonant circuit is called as thecircuit.
A.    Selector
B. Rejecter
C. Voltage amplifier
D. None of above
Answer-B
109.  The reactive power is also called aspower and it expressed in.
A.    True, VAR
B. Imaginary, VAR
C. Imaginary, VA
D. Real , VA
Answer-B
110.  All the home appliances operates on Voltage.
A.    AC
B. DC
C. AC or DC
D. None of the above
Answer-A
111.  In the equation V(t) = Vm × Sin(wt), V(t) indicates theValue            .
A.    RMS
B. Peak
C. Instantaneous
D. Average
Answer-C
BASIC ELECTRICAL MOST ASKED
112.  The instantaneous value of voltage at t=t1 is given by,
A.    V(t=t1)
B. V(t1)
C. V/t1
D. None of these
Answer-A
113.  One Cycle  is equal to
A.    π radian
B. 2π radian
C. 4π radian
D. 1800
Answer-B
114.  For a purely inductive circuit if the source voltage is V= Vm×sin(wt) then the equation of the current is given by,
A.    Im sin(wt)
B. Im sin(wt +π/2)
C. Im sin(wt – π/2)
D. Im sin(wt – π)
Answer-C
BASIC ELECTRICAL MOST ASKED
115.  The inductive reactance for DC is.
A.    Zero
B. Infinite
C. In between zero and infinite
D. None
Answer-A
116.  Impedance of a purely inductive circuit is expressed in polar form as, Z=Ω
A. Xl<-900
B. Xl<-00
C. Xl<900
D. Xl<1800
Answer-C
117.  The capacitive reactance XCwithin frequency.
A.    Increases, decreases
B. Decreases, Decreases
C. Increases, increases
D. Remains constant.
Answer-A
118.  The phase angle for an RL series circuit is given by,
A.    sin-1(Xl/R)
B. cos-1(Xl/R)
C. tan-1(Xl/R)
D. tan-1(R/Xl)
Answer-C
BASIC ELECTRICAL MOST ASKED
119.  The triangle is derived from triangle by dividing each side by
A.    Voltage, impedance, voltage
B. Impedance, voltage, voltage
C. Impedance, voltage, current
D. Voltage, impedance, current
Answer-C
120.  The frequency of the AC quantity is measured in.
A.    units/sec
B. cycles-sec
C. cycles/sec
D. Sec/cycles
Answer-C
121.  The lamp load is an example of …………….
A.    Purely resistive
B. Purely Inductiove
C. R-L sries
D. None
Answer-B
122.  The dynamic impedance represents theof the parallel resonanct circuit.
A.    Minimum value of impedance
B. Maximum value of impedance
C. RMS value of impedance
D. Avg value of impedance
Answer-B
BASIC ELECTRICAL MOST ASKED
123.  The exepression for parallel combination of impedance Z1 and Z2 is
A. (Z1+Z2)/ (Z1Z2)
B. (Z1+Z2)/ (Z1 -Z2)
C. (Z1  Z2)/ (Z1 +Z2)
D. (Z1 Z2)/ (Z1 -Z2)
Answer-C
124.  A pure indutor is equivalent to afro a direct current and voltage
A.    Open circuit
B. Short circuit
C. An open switch
D. None of these
Answer-B
125.  The reactive power is also called power and it is expressed in
A.    True,VAR
B. Imaginary,VAR
C. Imaginary,VA
D. Real,VA
Answer-B
126.  P.F. is equal to
A.    S/P
B. Q/P
C. P/S
D. S/Q
Answer-C