Electricity 5 Of 7 Flashcards
What are the four basic meters?
1-ammeter
2-voltmeter
3-ohmmeter
4-wattmeter
Can a current meter be calibrated in units other that amps?
Yes, in can be calibrated in voltage and resistance because all three are related to ohms law
When current flows through a wire, it produces what two effects?
1-it creates a magnetic field around the wire.
2- it generates heat
The _________ current meter makes use of the magnetic field around a current-carrying wire to measure current.
Electromagnetic
The ___________ meter uses the heat produced by a wire to measure current.
Thermal
The __________ of the magnetic field is proportional to the amount of ______________ flowing through the coil.
Strength
Current
What are the two types of electromagnetic current meters?
1) moving-coil type
2) moving-iron type
The first known moving-coil meter was called?
Galvanometer
Because it is very accurate and rugged, the _______________ is the most common meter used
Moving-coil movement
What are the three types of moving-iron meters?
1) radial vane
2) concentric-vane, and
3) plunger type
When current flows through a wire, the wire is heated_________ to the current flow.
Proportionally
In the concentric-vane meter, the stationary vane is ______ to provide a nonuniform magnetic field between the two vanes.
Tapered.
What are the typical three shapes of pointers?
Spade
Knife
Lance
The ___________ meter movement is used most often because it is more sensitive and more accurate.
Moving-coil
By using a _________ to convert ac to dc, moving-coil meters can be used in a-c applications.
Rectifier
