Instrumentation Transducers

Measurement of Voltage

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which of the following applications are electrostatic instruments suited for?
With AC quantities only
With AC and DC quantities
With DC quantities only
None of the mentioned
Explanation:
Electrostatic instruments are devices which can be used in both AC and DC quantities.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
What is the purpose of a differential amplifier in voltmeter?
Elimination of unwanted signals
To find difference of voltages
To eliminate DC components
To set a certain voltage level
Explanation:
Differential amplifiers is included in voltmeters to avoid any spurious signals, which may arise due to electrostatic stray field.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
A Multimeter is used to measure ___________
Only AC current
Only DC voltage
Both AC and DC quantities
Resistance only
Explanation:
Multimeter is a device which can be used to measure both AC and DC quantities and also resistance.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Which of the following unit is used to express the sensitivity of analog voltmeter?
Ohms
Voltage
No unit
Ohms per volt
Explanation:
Sensitivity of analog voltmeter is expressed in terms of ohms per volt. That is number of Ω resistance in meter circuit divided by the full scale measured value.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
In a CRO to which part saw tooth waveform is applied?
Horizontal amplifier
To fluorescent screen
Vertical deflection plate
Electron gun
Explanation:
Saw tooth wave is applied to the horizontal amplifier of CRO. Horizontal amplifier controls horizontal deflection plates.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
In a CRO what is the purpose of the blanking circuit?
To increase visual quality
To increase number of channels
To eliminate retrace of signals due to movement of spot
None of mentioned
Explanation:
Blanking circuit is used to eliminate retrace of signals when spot moves from left to right.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Which of the following can be the range of input impedance of voltmeter?
less than 1Ω
Between 1Ω and 10Ω
Very high
unpredictable
Explanation:
Input impedance of volt meter is of the order of 10MΩ. That is very high. Voltmeter has a high shunt resistance value.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Who invented the first digital voltmeter?
Edward Lawry Norton
Andrew Kay
Joseph Henry
Nicola tesla
Explanation:
Digital voltmeter gives output reading on digital format. It was invented by Andrew Kay.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Which of the following device can be used to measure low voltage?
VTVM
Moving iron voltmeter
CRO
None of the mentioned
Explanation:
CRO (Cathode ray oscilloscope) is a device which can be used to measure the voltage level of signals with a wide range of variation.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
What will be the sensitivity of a volt meter with 0 to 7mA meter movement?
143 Ω/ V
140 Ω/V
100 Ω/V
10 Ω/V
Explanation:
Sensitivity of a voltmeter is the reciprocal of maximum current deflection. It is expressed in unit Ω/V. here sensitivity is reciprocal of 7mA.