which torque is absent in energy meter? and why?
Answers
Answered by
2
Write the classification of measuring instruments. Electrical instruments are mainly classified as
a. Indicating instruments
b. Recording instruments
c. Integrating instruments
2. Define indicating instruments.
Indicating instruments are used to indicating the magnitude of unknown quantity. The examples are ammeters, voltmeters etc.
3. Define recording instruments.
These instruments give a continuous record of the given input quantity. The examples are various types of recorders.
4. Define integrating instruments.
These instruments measure the total quantity of electricity delivered over period of time. Example: energy meter.
5. What are the requirements of an instrument?
The following systems must be present in an instrument
a. Deflecting system producing deflecting torque.
b. Controlling system producing controlling torque.
c. Damping system producing damping torque.
6. What are the types of instruments? It consist of two types
(i) Permanent magnet moving coil instrument.
(ii) Moving iron instruments
a. Moving iron attraction type.
b. Moving iron repulsion type.
7. What are the advantages of digital instruments over analog instruments?
a. High accuracy.
b. High input impedance.
c. Reading speed is very high.
d. Digital output can be directly recorded.
8. Define gravity control.
It consists of a small weight attached to the moving system. Whose position is adjustable. This weight produces a controlling torque due to gravity.
9. Define spring control.
In this system two hair springs are attached to the moving system which produce the controlling torque.
10. Explain the purpose of Schmitt trigger in digital frequency meter.
In a digital frequency meter, Schmitt trigger is connected between amplifier and a gate, it is used to convert the analog voltage from the amplifier to train of pulses which is fed to the gate.
11. Which torque is absent in energy meter? Why?
In energy meter, there is no controlling torque, as the driving torque alone is enough to cause continuous revolution of the disc.
12. What are the various principles of analog type electrical instruments?
a. Magnetic effect
b. Heating effect
c. Electrostatic effect
d. Electromagnetic effect
e. Hall effect
13. What is the principle of ramp type digital voltmeter?
Ramp type digital volt meter works on the principle of comparison of unknown voltage with the ramp signal and by counting the number of pulses passing through till both the voltages become equal. This number of pulse will give the direct indication of the voltage.
14. What is the purpose of instrument transformers?
The transformers used for measuring very large values of current or voltage which can not be directly measured are called instrument transformer. Two types of instrument transformers are
a. Current transformer
b. Voltage transformer.
15. How a PMMC meter can be used as voltmet
a. Indicating instruments
b. Recording instruments
c. Integrating instruments
2. Define indicating instruments.
Indicating instruments are used to indicating the magnitude of unknown quantity. The examples are ammeters, voltmeters etc.
3. Define recording instruments.
These instruments give a continuous record of the given input quantity. The examples are various types of recorders.
4. Define integrating instruments.
These instruments measure the total quantity of electricity delivered over period of time. Example: energy meter.
5. What are the requirements of an instrument?
The following systems must be present in an instrument
a. Deflecting system producing deflecting torque.
b. Controlling system producing controlling torque.
c. Damping system producing damping torque.
6. What are the types of instruments? It consist of two types
(i) Permanent magnet moving coil instrument.
(ii) Moving iron instruments
a. Moving iron attraction type.
b. Moving iron repulsion type.
7. What are the advantages of digital instruments over analog instruments?
a. High accuracy.
b. High input impedance.
c. Reading speed is very high.
d. Digital output can be directly recorded.
8. Define gravity control.
It consists of a small weight attached to the moving system. Whose position is adjustable. This weight produces a controlling torque due to gravity.
9. Define spring control.
In this system two hair springs are attached to the moving system which produce the controlling torque.
10. Explain the purpose of Schmitt trigger in digital frequency meter.
In a digital frequency meter, Schmitt trigger is connected between amplifier and a gate, it is used to convert the analog voltage from the amplifier to train of pulses which is fed to the gate.
11. Which torque is absent in energy meter? Why?
In energy meter, there is no controlling torque, as the driving torque alone is enough to cause continuous revolution of the disc.
12. What are the various principles of analog type electrical instruments?
a. Magnetic effect
b. Heating effect
c. Electrostatic effect
d. Electromagnetic effect
e. Hall effect
13. What is the principle of ramp type digital voltmeter?
Ramp type digital volt meter works on the principle of comparison of unknown voltage with the ramp signal and by counting the number of pulses passing through till both the voltages become equal. This number of pulse will give the direct indication of the voltage.
14. What is the purpose of instrument transformers?
The transformers used for measuring very large values of current or voltage which can not be directly measured are called instrument transformer. Two types of instrument transformers are
a. Current transformer
b. Voltage transformer.
15. How a PMMC meter can be used as voltmet
Similar questions