Podcast
Questions and Answers
Why does waveform error occur in MI instruments?
Why does waveform error occur in MI instruments?
- The current coil is designed to carry less than 20 amperes
- Deflection torque is directly proportional to the square of the current (correct)
- The fixed coil is not air-cored
- The pointer mounts on the fixed coil
What provides the controlling torque to the electrodynamometer wattmeter?
What provides the controlling torque to the electrodynamometer wattmeter?
- Moving coil
- Eddy current
- Fixed coil
- Spring control system (correct)
What causes serious errors in dynamometer type wattmeters at low power factors?
What causes serious errors in dynamometer type wattmeters at low power factors?
- Movement of the pointer
- Enclosure in an iron case
- Inductance of the potential coil (correct)
- Use of linear scale
What is the function of the fixed coil in the electrodynamometer wattmeter?
What is the function of the fixed coil in the electrodynamometer wattmeter?
Why is magnetic shielding provided in dynamometer type wattmeters?
Why is magnetic shielding provided in dynamometer type wattmeters?
What symbol is used to represent current?
What symbol is used to represent current?
In which way should an ammeter be connected in a circuit to measure current?
In which way should an ammeter be connected in a circuit to measure current?
What is the main reason why an ammeter should never be connected in parallel with any circuit component?
What is the main reason why an ammeter should never be connected in parallel with any circuit component?
Which instrument should be used to measure potential difference or voltage?
Which instrument should be used to measure potential difference or voltage?
Why are ammeters manufactured with very low values of internal resistance?
Why are ammeters manufactured with very low values of internal resistance?
Why must a voltmeter be connected in parallel in a circuit?
Why must a voltmeter be connected in parallel in a circuit?
What is the purpose of manufacturing voltmeters with a very high internal resistance?
What is the purpose of manufacturing voltmeters with a very high internal resistance?
In a moving iron instrument, what type of force allows the iron plate to deflect from low magnetic field to high magnetic field?
In a moving iron instrument, what type of force allows the iron plate to deflect from low magnetic field to high magnetic field?
What feature allows moving iron instruments to be used for both AC and DC?
What feature allows moving iron instruments to be used for both AC and DC?
What is a disadvantage of moving iron instruments that hinders accurate readings?
What is a disadvantage of moving iron instruments that hinders accurate readings?
What is the main component of the driving system in a single-phase energy meter?
What is the main component of the driving system in a single-phase energy meter?
In the moving system of an energy meter, what induces the eddy current in the aluminium disc?
In the moving system of an energy meter, what induces the eddy current in the aluminium disc?
What material is the coil former typically made of in a PMMC instrument?
What material is the coil former typically made of in a PMMC instrument?
How does the braking system in an energy meter reduce the rotation of the aluminium disc?
How does the braking system in an energy meter reduce the rotation of the aluminium disc?
What is the main function of the registration or counting mechanism in an energy meter?
What is the main function of the registration or counting mechanism in an energy meter?
What component is responsible for producing the damping torque in a PMMC instrument?
What component is responsible for producing the damping torque in a PMMC instrument?
What does PMMC stand for in the context of energy meter instrumentation?
What does PMMC stand for in the context of energy meter instrumentation?
What are the permanent magnets in a PMMC instrument typically made of?
What are the permanent magnets in a PMMC instrument typically made of?
Which material is typically used to make the control springs in a PMMC instrument?
Which material is typically used to make the control springs in a PMMC instrument?
What generates the mechanical torque that acts on the coil in a PMMC instrument?
What generates the mechanical torque that acts on the coil in a PMMC instrument?
What is a key advantage of using a PMMC Instrument for measurements?
What is a key advantage of using a PMMC Instrument for measurements?
Why is the linear scale of a PMMC Instrument divided uniformly?
Why is the linear scale of a PMMC Instrument divided uniformly?
Why does a PMMC Instrument use eddy current damping?
Why does a PMMC Instrument use eddy current damping?
Which is a common disadvantage of the PMMC Instrument?
Which is a common disadvantage of the PMMC Instrument?
Why is earthing important in electrical systems?
Why is earthing important in electrical systems?
What is the depth at which the copper plate is placed for plate earthing?
What is the depth at which the copper plate is placed for plate earthing?
What material is used to keep the earth electrode resistance value below 5 ohms in plate earthing?
What material is used to keep the earth electrode resistance value below 5 ohms in plate earthing?
What is the diameter of the galvanized iron pipe used for pipe earthing?
What is the diameter of the galvanized iron pipe used for pipe earthing?
How deep is the GI iron pipe placed for pipe earthing?
How deep is the GI iron pipe placed for pipe earthing?
What mixture is used to fill the area surrounding the GI iron pipe in pipe earthing?
What mixture is used to fill the area surrounding the GI iron pipe in pipe earthing?
According to the provided text, what should be done if there is any accidental contact of a person with a live wire?
According to the provided text, what should be done if there is any accidental contact of a person with a live wire?
What types of tools are recommended to be used while working with electricity?
What types of tools are recommended to be used while working with electricity?
What should be avoided when working with electricity according to the text?
What should be avoided when working with electricity according to the text?
In case of any short-circuiting or accidental contact with a live wire, what should be done before anything else?
In case of any short-circuiting or accidental contact with a live wire, what should be done before anything else?
What should be done to prevent accidental shocks according to the text?
What should be done to prevent accidental shocks according to the text?
