Meters Flashcards
A1. A special type of ohmmeter used for measuring extremely high resistances is called a megohmeter (megger). This meter is capable of measuring these high resistances because:
It uses a magnetogenerator as the power supply
A2. In order to measure large currents with the D’Arsonval ammeter:
Shunts are used
A4. An ohmmeter is constructed by using a simple galvanometer (moving coil) type meter movement and adding:
Battery
Series resistor
Rheostat
A5. A complete voltmeter must be a high resistance instrument because:
A large current must flow through the meter coil
A6. A dynamometer meter movement may be used to measure alternating current because:
The polarity of the coil and the magnets are changed with each alternation of the current
A7. To check leakage in a high voltage shielded cable, you would use a:
Megger
A8. The three general classifications of meters are:
Ammeter
Voltmeter
Ohmmeter
A9. A small battery, a light bulb, and two wire leads can be used to check _____.
Continuity
A10. What two instruments are most commonly used to check the continuity of a circuit?
Voltmeter
Ohmmeter
A11. The most satisfactory movement for the measurement of high alternating current is the _____.
Thermocouple meter
A13. An ammeter is always connected in a circuit in series because:
It has a very low internal resistance
A14. When using an ohmmeter to determine resistance of a lamp in a circuit:
All power to the lamp must be off
A15. What is the proper method when connecting voltmeters and ammeters in an airplane electrical circuit?
Ammeter in series
Voltmeter in parallel
A16. When instruments, including electrical types, do not give proper indications they should be _____.
Sent to an approved instrument overhaul and repair shop or returned to the manufacturer for servicing
A18. Jeweled bearings are used in meter movements because ____
The amount of friction they produce is minimal
A19. To determine the amount of current flow in a circuit, you would use _____.
An ammeter
A20. A shunt resistance is used in most ammeters because it makes it possible to use the same meter movement for a wide range of current measurement. The larger the current being measured, the ____.
The higher the voltage drop across the shunt
A21. What two devices are used to measure resistance?
Megger
Ohmmeter
A22. A voltmeter is used to measure the ____
Current at any one point in the circuit
8083 - Both the ammeter and the voltmeter are current measuring instruments
A23. In a D’Arsonval type meter, the primary purpose of the iron core is to _____
Concentrate the flux between the core and the pole piece
A24. The presence of an internal shunt identifies the meter as _____
an Ammeter
B1. The three general classifications of meters are ___
Ammeter
Voltmeter
Ohmmeter
B2. When using a voltmeter to test a circuit, it must be connected in _____
Parallel
B4. What two devices are used to measure resistance?
Megger and ohmmeter
B5. A basic DC D’Arsonval meter is dependent for operation on
??? Equal but opposite electron potential ???
B6. In order to measure large currents with the D’Arsonval ammeter, ____
Shunts are used
B7. A shunt resistance is used in most ammeters because it makes it possible to use the same meter movement for a voltage range of current measurement. The larger the current being measured, the ______
Lower the resistance of the shunt allowing more current to flow through the shunt
B8. To determine the amount of current flow in a circuit, you would use a ____
Ammeter
B9. Jeweled bearings are used in meter movements because ____
The amount of friction they produce is minimal
B10. A dynamometer meter movement may be used to measure alternating current because _____
The polarity of the coil and the magnets are changed with each alternation of the current
B11. The presence of an internal shunt identifies the meter as a ____
an Ammeter
B12. To check leakage in a high voltage shielded cable, you would use a ____
Megger
B13. An ammeter is always connected in a circuit in a series because _____
It has a very low internal resistance
B14. What two instruments are most commonly used to check the continuity of a circuit?
Voltmeter
Ohmmeter
B15. An ammeter should be installed in a circuit in such a manner that ____
The positive terminal of the meter is connected to the positive battery terminal
B16. What determines the amount of needle deflection of a D’Arsonval meter?
The number of windings and the magnetic force
B17. What is the proper method when connecting voltmeters and ammeters in an airplane electrical circuit?
Ammeters in series
Voltage in parallel
B18. A small batter, a light bulb, and two wire leads can be used to check ____
Continuity
B19. The voltage developed in the thermocouple type meter depends on the ____
Material of which the wires are made
B20. In a D’Arsonval type meter, the primary purpose of the iron core is to ____
Concentrate the flux between the core and the pole piece
C1. What two devices are used to measure resistance?
Megger
Ohmmeter
C2. The presence of an internal shunt identifies the meter as a ____
Ammeter
C3. What determines the amount of needle deflection of a D’Arsonval meter?
The number of windings and the magnetic force
C4. A shunt resistance is used in most ammeters because it makes it possible to use the same meter movement for a wide range of current measurement. The larger the current being measured, the ____
Lower the resistance of the shunt allowing more current to flow through the shunt
C5. Jeweled bearings are used in meter movements because ____
The amount of friction they produce is minimal
C6. When using an ohmmeter to determine resistance of a lamp in a circuit, ____
All power to the lamp must be off
C7. When instruments, including electrical types, do not give proper indications, they should be ____
Sent to an approved instrument overhaul and repair shop or the manufacturer for servicing
C8. The three general classifications of meters are ____
Ammeter
Voltmeter
Ohmmeter
C11. What is the proper method when connecting voltmeters and ammeters in an airplane electrical circuit?
Ammeters in series
Voltmeters in parallel
C12. In order to measure large currents with the D’Arsonval ammeter, ____
Shunts are used
C13. In a D’Arsonval type meter, the primary purpose of the iron core is to _____
Concentrate flux between the core and the pole piece
C14. An ohmmeter may be constructed by using a simple galvanometer (moving coil) type meter movement and adding a ____
Battery
Series resistor
Rheostat
C15. What two instruments are most commonly used to check the continuity of a circuit?
Voltmeter
Ohmmeter