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Free download in PDF Electrical Measuring Instruments Multiple Choice Questions & Answers for competitive exams. These objective type questions are very important for competitive exams of Engineering. These short solved questions or quizzes are provided by Gkseries.
(1)
Hysteresis of an instrument means:
[A]
The change in the same reading when input is first increased and then decreased
[B]
The reliability of the instrument
[C]
The repeatability of the insrument
[D]
The inaccuracy due to change in temperature
Answer: The change in the same reading when input is first increased and then decreased
(2)
In which part of the scale does the pointer indicate more accurately
[A]
In the first third of the cycle
[B]
In the first half of the cycle
[C]
In about middle of the scale
[D]
In the last third of the cycle
Answer: In about middle of the scale
(3)
A 150 V moving iron voltmeter of accuracy class 1.0 reads 75 V when used in a circuit under a standard conditions. The maximum possible percentage error in the reading is:
[A]
0.5
[B]
1.0
[C]
2.0
[D]
4.0
(4)
The moving iron voltmeters are likely:
[A]
To indicate the same value of the ac as on dc
[B]
To indicate higher value of ac than on dc
[C]
To indicate lower value of ac than on dc
[D]
The moving iron instruments should not be used for dc measurment
Answer: To indicate lower value of ac than on dc
(5)
Hay’s Bridge is suitable for the measurement of:
[A]
Inductances with Q>10
[B]
Inductances with Q<10
[C]
Capacitors with high dissipation factor
[D]
Capacitors with low dissipation factor
Answer: Inductances with Q>10
(6)
The ballistic galvanometer is usually lightly damped so that:
[A]
It may oscillate
[B]
It may remain stable
[C]
Amplitude of the first swing is large
[D]
Amplitude of the first swing is small
Answer: Amplitude of the first swing is large
(7)
Magnetic materials can be tested by:
[A]
Self inductance bridge
[B]
Cambell’s mutual inductance bridge
[C]
AC potentiometer
[D]
All the above
(8)
In CRO astigmatism is:
[A]
Source of generating fast electrons
[B]
Media for absorbing secondary emission electrons
[C]
An additional focus control
[D]
Time-delay control in the vertical deflection system
Answer: An additional focus control
(9)
Moving iron and PMMC instruments can be distinguished from each other by looking at:
[A]
Pointer
[B]
Terminal size
[C]
Scale
[D]
Scale range
(10)
The deflection of hot-wire instrument depends on:
[A]
Instantaneous value of alternating current
[B]
Average value of current
[C]
RMS value of the alternating current
[D]
Voltage
Answer: RMS value of the alternating current
(11)
The damping torque must operate only when the moving system of the indicating instrument is:
[A]
Actually moving
[B]
Stationary
[C]
Just starting to move
[D]
Near its full deflection
(12)
Air friction damping is used in the instruments which is:
[A]
Moving iron
[B]
Moving coil
[C]
Induction
[D]
Hot wire
(13)
An instrument that is capable of measuring only dc is:
[A]
Moving coil
[B]
Moving iron
[C]
Thermo couple
[D]
None of the above
(14)
A ballistic galvanometer is used to measure:
[A]
Charge
[B]
Current
[C]
Voltage
[D]
Frequency
(15)
For measuring emf of a standard cell we use:
[A]
Galvanometer
[B]
Potentiometer
[C]
Zener reference
[D]
Electro-dynamic voltmeter
(16)
Introduction of dielectric:
[A]
Increases the capacitance
[B]
Reduces the breakdown voltage
[C]
Reduces the mechanical voltage
[D]
Increases the size of the capacitor
Answer: Increases the capacitance
(17)
Which of the following instruments have least torque/weight ratio:
[A]
Dynamometer type
[B]
PMMC
[C]
Attraction type moving iron
[D]
Repulsion type moving iron
(18)
The instrument having its deflection depends upon average value is:
[A]
Moving iron
[B]
Hot wire
[C]
Rectifier type
[D]
Induction type
(19)
Which of the following instruments can be used for full scale deflection of 300o:
[A]
PMMC
[B]
Induction type
[C]
Hot wire
[D]
Electrostatic
(20)
A Ohmmeter is basically:
[A]
A ammeter
[B]
A voltmeter
[C]
A multimeter
[D]
None of the above
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