Explore topic-wise MCQs in Electrical Engineering Questions.

This section includes 306 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.

51.

In a spring controlled type indicating instruments, if the controlling torque is equal to the deflecting torque then
A. Angle of deflection will be maximum
B. Current flowing through it will be maximum
C. Angle of deflection will be zero
D. Angle of deflection will be directly proportional to the current flowing through it
Answer» E.
Discussion
52.

Suitable method for the reduction of systematic errors is/are
A. Instrument must be designed carefully
B. By introducing an equal and opposite environmental input for compensating the effect of environmental input in a measurement system
C. By adding high gain feedback to measurement system
D. All of these
Answer» E.
Discussion
53.

If the instrument is used in wrong manner while application, then it will results in
A. Systematic error
B. Instrument error
C. Random error
D. Environmental error
Answer» C. Random error
Discussion
54.

The undesirable characteristics of a measuring system is / are
A. Drift
B. Dead zone
C. Non linearity
D. All of these
Answer» E.
Discussion
55.

The systematic errors of an instrument can be reduced by making
A. The sensitivity of instrument to environmental input as low as possible
B. The sensitivity of instrument to environmental input as high as possible
C. Systematic errors does not depend on the sensitivity of instrument
D. None of these
Answer» B. The sensitivity of instrument to environmental input as high as possible
Discussion
56.

If the quantity to be measured remains constant during the process of taking the repeated measurements then the random errors can be eliminated by
A. Calculating the mean of the number of repeated measurements
B. Calculating the median of the number of repeated measurements
C. Calculating the sum of the numbers of repeated measurements
D. Either (a) or (b)
Answer» E.
Discussion
57.

When a 100 V moving iron voltmeter is of accuracy class 1-0 is used in a circuit, it reads 50 V. Then the maximum possible percentage error in the reading is
A. 1 %
B. 2 %
C. 2.5 %
D. 3 %
Answer» C. 2.5 %
Discussion
58.

The deflecting torque in a permanent magnet moving coil type instrument is
A. Directly proportional to the angle of deflection of moving system
B. Directly proportional to the current flowing through it
C. Directly proportional to the current flowing through it
D. Inversely proportional to the current flowing through it
Answer» C. Directly proportional to the current flowing through it
Discussion
59.

In indicating instruments, the controlling and restoring torque can be obtained by using
A. Spring
B. Gravity
C. Either by spring or by gravity
D. Neither by spring nor by gravity
Answer» D. Neither by spring nor by gravity
Discussion
60.

If the resistance in a circuit is given by 80Ω ± 0.2% and the current flowing through it is 5A ± 0.1%, then the uncertainty in the power will be
A. ± 0.2 %
B. ± 0.4 %
C. ± 0.6 %
D. ± 0.8 %
Answer» C. ± 0.6 %
Discussion
61.

The restoring torque in a spring controlled indicating instrument is
A. Directly proportional to the angle of deflection of moving system
B. Directly proportional to the sine of angle of deflection of moving system
C. Inversely proportional to the angle of deflection of moving system
D. Directly proportional to the square of the angle of deflection of moving system
Answer» B. Directly proportional to the sine of angle of deflection of moving system
Discussion
62.

The damping force in an instrument can be produced by air friction, eddy currents and fluid friction. Which among the three is most efficient?
A. Air friction
B. Eddy current
C. Fluid friction
D. All are equally efficient
Answer» C. Fluid friction
Discussion
63.

Damping torque is the torque which acts on
A. Stationary system of the instrument
B. Moving system of the instrument only when it is stationary
C. Moving system of the instrument only when it is moving
D. Stationary system of the instrument only when the moving system is moving
Answer» D. Stationary system of the instrument only when the moving system is moving
Discussion
64.

In measuring instruments, spiral springs are provided to
A. Lead current
B. Produce controlling torque
C. Produce damping torque
D. Lead current and produce controlling torque
Answer» E.
Discussion
65.

A spring controlled moving iron voltmeter with full scale deflection of 150 V draws a current of 2 mA. What will be the meter reading if it draws a current of 1 mA?
A. 25.5 V
B. 27.5 V
C. 35.5 V
D. 37.5 V
Answer» E.
Discussion
66.

If a balloon is equipped with temperature and altitude measuring instruments, then the order of the temperature measuring and altitude measuring instruments are
A. Zero order, first order
B. Both are first order instruments
C. Both are zero order instruments
D. First order, zero order
Answer» E.
Discussion
67.

Example for positive displacement meter is
A. Variable area flow meter
B. Turbine meters
C. Rotary piston meter
D. Venturi
Answer» D. Venturi
Discussion
68.

If a moving iron instrument is to be used as ammeter then the coil has
A. Fewer number of turns of thin wire
B. Fewer number of turns of thick wire
C. Larger number of turns of thin wire
D. Larger number of turns of thick wire
Answer» C. Larger number of turns of thin wire
Discussion
69.

If the degree of damping of an instrument should be adjusted to a value which is sufficient to enable the pointer to rise quickly to its deflected position without overshooting is called as
A. Overdamped
B. Dead beat
C. Underdamped
D. None of these
Answer» C. Underdamped
Discussion
70.

Due to overdamping, the instrument will become
A. Slow
B. Lethargic
C. Fast
D. Both (a) and (b)
E. None of these
Answer» E. None of these
Discussion
71.

The time response of an indicating instrument is determined from the
A. Damping torque
B. Controlling torque
C. Deflecting torque
D. All of these
Answer» B. Controlling torque
Discussion
72.

A voltmeter connected across an unknown resistance has scale of 0 to 150 V reads 50 V when the current flowing in the circuit is 1 mA. If sensitivity of the voltmeter is 15kΩ/V, then the percentage error due to loading effect is
A. ± 1.5%
B. ± 2.12%
C. ± 2.22%
D. ± 2.5%
Answer» D. ± 2.5%
Discussion
73.

A repulsion type moving iron instrument when used with a.c. circuits, the deflecting torque is
A. Directly proportional to the rms current
B. Directly proportional to the square of rms current
C. Directly proportional to the peak current
D. Directly proportional to the square of the peak current
Answer» C. Directly proportional to the peak current
Discussion
74.

If the direction of current through the coil is upward, then the iron disc will be magnetized in such a way that it is
A. Pushed outwards
B. Pushed upwards
C. Pushed downwards
D. Pulled inwards
Answer» E.
Discussion
75.

An ac voltage source of 2sint V is connected in series with a dc voltage source of 5 V. If a PMMC instrument is connected in parallel to this combination then the reading of meter will be equal to
A. 7 V
B. 5 V
C. 5.2 V
D. 25 V
Answer» C. 5.2 V
Discussion
76.

A PMMC instrument can be used as ammeter and as voltmeter with the help of
A. A low resistance shunt, a low series resistance
B. A low resistance shunt, a high series resistance
C. A high series resistance, a low resistance shunt
D. A low series resistance, a high shunt resistance
Answer» C. A high series resistance, a low resistance shunt
Discussion
77.

The deflecting torque in a moving coil instrument is
A. Directly proportional to the current flowing through it
B. Inversely proportional to the current flowing through it
C. Inversely proportional to the square of current flowing through it
D. Directly proportional to the square of current flowing through it
Answer» E.
Discussion
78.

When an ac signal is applied across the permanent magnet moving coil voltmeter, then the pointer will
A. Not deflect
B. Oscillate around zero volt
C. Deflect to its maximum
D. Oscillate from minimum to maximum value
Answer» C. Deflect to its maximum
Discussion
79.

In a PMMC instrument, if the control springs are eliminated the instrument can be used for measuring the quantity of electricity passed through the coil. This method is used for
A. Ammeter
B. Voltmeter
C. Fluxmeter
D. Ballistic galvanometer
Answer» D. Ballistic galvanometer
Discussion
80.

If the control spring of PMMC instrument is replaced by a another spring whose spring constant is higher than the previous one, then the damping ratio and natural frequency
A. Increases, decreases
B. Increases, increases
C. Decreases, decreases
D. Decreases, increases
Answer» B. Increases, increases
Discussion
81.

A moving coil ammeter requires a potential difference of 0.4V across it for full scale deflection. It has fixed shunt resistance of 0.01 ohm with a coil circuit resistance of R = 1kohm. The value of shunt required to give full scale deflection when the total current is 10A is equal to
A. 0.02 ohm
B. 0.04 ohm
C. 0.05 ohm
D. 0.06 ohm
Answer» C. 0.05 ohm
Discussion
82.

If the control springs of PMMC instrument is made up of large moment of inertia, then it can be used as
A. Ammeter
B. Fluxmeter
C. Ballistic galvanometer
D. Wattmeter
Answer» D. Wattmeter
Discussion
83.

The thermocouple instruments works on the principle of Seebeck effect. The amount of heat produced is
A. Directly proportional to the current
B. Directly proportional to the square of current
C. Inversely proportional to the current
D. Inversely proportional to the square of current
Answer» C. Inversely proportional to the current
Discussion
84.

Power consumption in permanent magnet moving coil instrument and hot-wire instruments are
A. Low, low
B. Low, high
C. High, low
D. High, high
Answer» C. High, low
Discussion
85.

A PMMC instrument gives full scale deflection at 40 mV potential difference and 8 mA current. What will be the required shunt resistance when it is used as ammeter of range 0 – 10 A?
A. 0.002 ohm
B. 0.003 ohm
C. 0.004 ohm
D. 0.005 ohm
Answer» D. 0.005 ohm
Discussion
86.

A permanent magnet moving coil gives full scale deflection at 40 mV potential difference and 8 mA current. What will be the required series resistance when it is used as voltmeter of range 0 – 200 V?
A. 19556 ohm
B. 20163 ohm
C. 23884 ohm
D. 24995 ohm
Answer» E.
Discussion
87.

In electrodynamic instruments, the operating field is produced by
A. Permanent magnet
B. Fixed coil
C. Moving coil
D. All of these
Answer» C. Moving coil
Discussion
88.

In the given frequency range, which type of instrument will have highest accuracy
A. electrodynamometer
B. hot-wire instrument
C. electrostatic instrument
D. PMMC
Answer» B. hot-wire instrument
Discussion
89.

The frequency errors in induction instruments can be compensated by the use of
A. Non inductive shunt in both ammeters and voltmeters
B. Non inductive shunt in case of ammeters and are generally self compensated in case of voltmeters
C. Self compensated in case of both ammeters and voltmeters
D. Self compensated in case of ammeters and non inductive shunt in case of voltmeters
Answer» C. Self compensated in case of both ammeters and voltmeters
Discussion
90.

In a portable instrument, the effect of stray magnetic field on actuating torque will be maximum when the operating field and stray fields are
A. Parallel to each other
B. Perpendicular to each other
C. Inclined at 45 degree
D. Opposite to each other
Answer» B. Perpendicular to each other
Discussion
91.

The range of electrostatic voltmeter can be extended by using
A. Resistance potential divider method
B. Capacitance potential divider method
C. Both (a) and (b)
D. None of these
Answer» D. None of these
Discussion
92.

For reducing the errors in an induction instrument the alternating current to be measured has
A. Same frequency with which the instrument was calibrated
B. High frequency compared with which the instrument was calibrated
C. Low frequency compared with which the instrument was calibrated
D. None of these
Answer» B. High frequency compared with which the instrument was calibrated
Discussion
93.

The temperature errors in induction instruments can be compensated by
A. Hunting in both ammeters and voltmeters
B. Combination of shunt and swamping resistance in both ammeters and voltmeters
C. Hunting in case of ammeters and Combination of shunt and swamping resistance in case of voltmeters
D. Combination of shunt and swamping resistance in case of ammeters and hunting in case of voltmeters
Answer» D. Combination of shunt and swamping resistance in case of ammeters and hunting in case of voltmeters
Discussion
94.

If an electrostatic voltmeter is used on AC circuit and has non uniform waves, then it will read
A. Average values
B. RMS values
C. Peak values
D. All of these
Answer» C. Peak values
Discussion
95.

The unit of luminance is
A. Lumen
B. Candela per square meter
C. Lux
D. Lumen per square meter
Answer» C. Lux
Discussion
96.

Which among the following is not true about the induction instruments?
A. It can be used for ac measurements only
B. Damping is very efficient in case of induction instruments
C. Compensation for frequency temperature is not required
D. Cost is relatively high
Answer» D. Cost is relatively high
Discussion
97.

In a moving coil of a meter swamping resistance is added to
A. Reduce the frequency error
B. Reduce the temperature error
C. Reduce the power consumption
D. All of these
Answer» C. Reduce the power consumption
Discussion
98.

In electrostatic instruments iron is not used in their construction. These instruments are
A. Free from hysteresis and eddy current losses
B. Free from temperature errors
C. Dependent on temperature errors
D. Both (a) and (b)
Answer» E.
Discussion
99.

The indicating instruments with linear scale is
A. PMMC
B. Electrostatic instrument
C. Dynamometer instrument
D. Thermocouple instrument
Answer» B. Electrostatic instrument
Discussion
100.

The resistance potential divider method and capacitance potential divider method is used for
A. Both AC and DC
B. Former method can be used for both AC and DC and the later method can be used only for AC
C. Former method can be used for AC only and the later method can be used for both AC and DC
D. Former method can be used for DC only and the later method can be used only for AC
Answer» C. Former method can be used for AC only and the later method can be used for both AC and DC
Discussion