Electrical and Electronics Engineering MCQ
Monday, 1 June 2020
Sunday, 3 May 2020
The velocity of a travelling electromagnetic wave in free space is given by
(A) μ0 ε0
(B)√( μ0 ε0)
(C) 1/√( μ0 ε0)
(D) μ0 ε0
Answer - - C
A zero to 300 v voltmeter has a guaranteed accuracy of 1% full scale reading. The voltage measured by the instrument is 83V. The percent limiting error is:
(A) 0.95
(B) 1.81
(C) 3.62
(D) 4.85
Answer - - C
In a moving coil meters, damping is provided by
(A) Eddy current disk
(B) The aluminum fram of te coil
(C) Damping in the air tight chamber
(D) The coiled spring attached to the moving mechanism
Answer - - B
A synchronous motor is essentially a motor with
(A) Constant speed
(B) Leading power factor
(C) Unity power factor
(D) Lagging power factor
Answer - - A
The unique advantages of a hydropower plant are that it
(A) Burns no fuel
(B) Produces no pollution
(C) Is located in hills
(D) Both A and B
Answer - - D
The conductance of an electrical circuit is similar to the given in a magnetic circuit
(A) Flux
(B) Reluctance
(C) Permeance
(D) Relative permeability
Answer - - C
With the introduction of capacity of a capacitor
(A) Increases
(B) Decreases
(C) Does not change
(D) None of the above
Answer - - A
To increase the range of an ammeter
(A) A low resistance is connected in series with ammeter
(B) A low resistance connected in shunt with ammeter
(C) A high resistance connected in series with ammeter
(D) None of the above
Answer - - B
(A) μ0 ε0
(B)√( μ0 ε0)
(C) 1/√( μ0 ε0)
(D) μ0 ε0
Answer - - C
A zero to 300 v voltmeter has a guaranteed accuracy of 1% full scale reading. The voltage measured by the instrument is 83V. The percent limiting error is:
(A) 0.95
(B) 1.81
(C) 3.62
(D) 4.85
Answer - - C
In a moving coil meters, damping is provided by
(A) Eddy current disk
(B) The aluminum fram of te coil
(C) Damping in the air tight chamber
(D) The coiled spring attached to the moving mechanism
Answer - - B
A synchronous motor is essentially a motor with
(A) Constant speed
(B) Leading power factor
(C) Unity power factor
(D) Lagging power factor
Answer - - A
The unique advantages of a hydropower plant are that it
(A) Burns no fuel
(B) Produces no pollution
(C) Is located in hills
(D) Both A and B
Answer - - D
The conductance of an electrical circuit is similar to the given in a magnetic circuit
(A) Flux
(B) Reluctance
(C) Permeance
(D) Relative permeability
Answer - - C
With the introduction of capacity of a capacitor
(A) Increases
(B) Decreases
(C) Does not change
(D) None of the above
Answer - - A
To increase the range of an ammeter
(A) A low resistance is connected in series with ammeter
(B) A low resistance connected in shunt with ammeter
(C) A high resistance connected in series with ammeter
(D) None of the above
Answer - - B
Saturday, 2 May 2020
If the effect of ground is taken into account, then the capacitance of line to ground:
(A) decreases
(B) Increases
(C) remain unchanged
(D) becomes infinite
Answer - - A
The DC shunt motor. operating under unsaturated region develops the maximum mechanical power when the armature current is such that the motor back emf (E) and the applied voltage (V) to the motor terminal are related as:
(A) E=V
(B) E=V/2
(C) E= V/3
(D) E=V/4
Answer - -B
The unit of flux density is:
(A) Tesla
(B) A/mm
(C) N/m2
(D) Wb/m
Answer - - A
If a DC voltmeter is made from an ammeter having a full scale deflection of 100 uA, then its sensitivity (in KΩ /V) will be:
(A) 1
(B) 10
(C) 100
(D) 1000
(A) 1
(B) 10
(C) 100
(D) 1000
Answer - - B
The impedance of a high Q inductor can be measured using:
(A) Schering bridge
(B) Wien Bridge
(C) Maxwell bridge
(D) Hay bridge
Answer - - D
The time taken for a range to travel a 600 km long overhead transmission line is:
(A) 6s
(B) 1s
(C) 0.02 s
(D) 0.002 s
Answer - - D
A star/delta starter of a 3 phase induction motor is equivalent to an autotransformer starter having a tapping of:
(A) √3/2
(B) 1/2
(C) 1/√3
(D) √3
Answer - - C
The amplifier has a voltage gain of 100. To induce distortion, 10% negative is employed. The gain of the amplifier with feedback is:
(A) 1.01
(B) 9.09
(C) 90.9
(D) 101
Answer - - C
Thursday, 30 April 2020
A crystal oscillator :
(A) Gives high output voltage
(B) Works at high efficiency
(C) Frequency of oscillation remains constant
(D) Requires very low DC supply
Answer - - C
In a load flow study if |V|and |δ| are specified at a bus. This bus is known as :
(A) Slack bus
(B) Load bus
(C) Voltage controlled bus
(D) None of these
Answer - - A
If P, be the iron loss and P, be the full load copper loss in a transformer, the ratio of rated load current to load current at which maximum efficiency occurs is:
(A) (Pi/Pc) ^1/2
(B) (Pc/Pi) ^1/2
(C) Pi/Pc
(D) Pc/Pi
Answer - - A
The power factor under-excited synchronous motor is always
(A) Leading
(B) Lagging
(C) Unity
(D) more than unity
Answer - - B
A source has an emf of 10 V and an impedance of (500+j100) ohms. The amount of maximum power transferred to the load will be
(A) 0.5 mw
(B) 0.05 mw
(C) 0.05 w
(D) 0.5 w
Answer - - C
A DC series motor should not be started
(A) at full load
(B) at no load
(C) with half of the full load
(D) none of the above
Answer - - A
The surge impedance of 400 km long overhead transmission line is 400 ohms, For a 200 km length of the same line, the surge impedance :
(A) 200 ohm
(B) 800 ohm
(C) 400 ohm
(D) 100 ohm
Answer - - C
The insulation strength of a EHV transmission line is mainly governed by :
(A) Load power factor
(B) Harmonies
(C) Corona
(D) Switching over voltage
Answer - - D
Wednesday, 29 April 2020
A cavity is a
(A) Low pass filter
(B) High pass fiter
(C) Band pass filter
(D) None of these
Answer - - C
The power factor of an alternator is determined by its
(A) Speed
(B) Load
(C) Excitation
(D) Prime mover
Answer - - B
An 8 pole wave connected d.c. generator has 900 armature conductors and a flux per pole of0.04 Wb. At what speed if must be driven to generator 500 V?
(A) 208.33 r.p.m
(B) 20.833 r.p.m.
(C) 900 r.p.m.
(D) 1600 r.p.m.
Answer - - A
A. shunt d.c. motor of armature circuit resistance 0.25 is connected to a 230 volt d.c. supply. The input line current is 8 A and the shunt field current 0.8 A. The e.m.f. generated in the armature is
(A) 230 V
(B) 228.2 V
(C) 231.8 V
(D) 250 V
Answer - - B
The........current of a junction FET (JFET) is practically zero.
(A) Anode
(B) Gate
(C) Cathode
(D) All of the above
(A) Anode
(B) Gate
(C) Cathode
(D) All of the above
Answer - - B
The difference between the measured value and the true value is called-
(A) Gross error
(B) Relative error
(C) Probable error
(D) Absolute error
Answer - - D
Ring main distribution system is more reliable because of-
(A) More protective devices used
(B) Two or more sources of supply
(C) Higher size of conductor used
(D) Higher load current
Answer - - B
Given (135)base x + (144)base x = (323)base x. What is the value of X ?
(A) 5
(B) 3
(C) 12
(D) 6
Answer - - D
Tuesday, 28 April 2020
Which of the following combination of a 3 phase transformer can successfully operate in parallel
For successful working of ground wire, the footing resistance of tower should be
( A) Low
(B) High
(C) Medium
(D) None of these
(A) Y-Y and Y- Δ
(B) Δ-Y and Δ-Δ
(C) Δ-Y and Δ-Y
(D) None of these
(B) Δ-Y and Δ-Δ
(C) Δ-Y and Δ-Y
(D) None of these
Answer - - C
A resistance of 20 ohm, an inductance of 0.2H and a capacitance of 100 uF are connected in series across a 220 V, 50 Hz supply. The impedance of the circuit is
(A) 71ohm
(B) 11ohm
(C) 3.690ohm
(D) 36.9ohm
(A) 71ohm
(B) 11ohm
(C) 3.690ohm
(D) 36.9ohm
Answer - - D
A 50 MVA, 1I KV, 39 alternator supplies full load at a lagging power factor of 0.7. What would be the percentage increase in earning capacity if the load power is increased to 0.95?
A 50 MVA, 1I KV, 39 alternator supplies full load at a lagging power factor of 0.7. What would be the percentage increase in earning capacity if the load power is increased to 0.95?
(A) 3. 57%
(B) 2.63%
(C) 26.3%
(D) 35.7%
(B) 2.63%
(C) 26.3%
(D) 35.7%
Answer - - D
The maximum demand on a power station is 100 MW. If the annual load factor is 40%, the total energy generated in a year will be
The maximum demand on a power station is 100 MW. If the annual load factor is 40%, the total energy generated in a year will be
(A) 3504 × 10^4 KWH
(B) 3504 × 10^5 KWH
(C) 3.504 × 10^4 KWH
(D) 3.504 × 10^5 KWH
(B) 3504 × 10^5 KWH
(C) 3.504 × 10^4 KWH
(D) 3.504 × 10^5 KWH
Answer - - B
For successful working of ground wire, the footing resistance of tower should be
( A) Low
(B) High
(C) Medium
(D) None of these
Answer - - A
A single phase line has two parallel conductors 2 meters apart. The diameter of each conductor is 1.2 cm, the loop inductance per km of the line will be
(A) 2.423 mH
(B) 24.23 mH
(C) 242.3 mH
(D) None of these
A single phase line has two parallel conductors 2 meters apart. The diameter of each conductor is 1.2 cm, the loop inductance per km of the line will be
(A) 2.423 mH
(B) 24.23 mH
(C) 242.3 mH
(D) None of these
Answer - - A
What is the value of flux in the section of yoke, if the pole flux is Ф weber?
A. Ф x Ф
B. Ф^1/2
C. Ф/2
D. Ф
Answer --C
A 220 V d.c. shunt motor runs at 500 rpm when the armature current is 50 A. If the torque is doubled, the speed will be. (given that Ra= 0.2 )
(A) 500 r.p.m.
(B) 476 r.p.m
(C)576 r.p.m.
(D) 525 r.p.m.
Answer--B
The 'V' curve of synchronous motor shows the relationship between
(A) Applied voltage and back e.m.f.
(B) Back e.m.f. and armature current
(C) Armature current and rotor field current
(D) Back e.m.f. and power factor
Answer--C
A. Ф x Ф
B. Ф^1/2
C. Ф/2
D. Ф
Answer --C
A 220 V d.c. shunt motor runs at 500 rpm when the armature current is 50 A. If the torque is doubled, the speed will be. (given that Ra= 0.2 )
(A) 500 r.p.m.
(B) 476 r.p.m
(C)576 r.p.m.
(D) 525 r.p.m.
Answer--B
The 'V' curve of synchronous motor shows the relationship between
(A) Applied voltage and back e.m.f.
(B) Back e.m.f. and armature current
(C) Armature current and rotor field current
(D) Back e.m.f. and power factor
Answer--C
Subscribe to:
Posts (Atom)