Properties of an AC circuit which opposes any change in current? (Alternating current)
Resistance, Inductive reactance and Capacitive reactance.
Describe impedance in AC circuit.
The total opposition to the current flow in an AC circuit consisting of either resistance and reactance, or elements of both capacitive or inductive.
What is common use of most multimeters?
Troubleshooting and measurements of voltage, resistance, current continuity, Capacitance and inductance.
Define Short Circuit.
Low resistance path between two poles (a component and/or a conductor and ground).
Using a multimeter, how would a technician read current?
Inserting the multimeter in series by opening or breaking the circuit. The positive side of the meter (RED) is connected towards the positive voltage source.
Why would you not perform a specific gravity check of electrolyte NI-CAD battery?
The specific gravity does not change with the state of charge.
How many cells make up a lead-acid battery rated at 24 volts?
12 cells.
When reading specific gravity of a fully charged lead-acid battery, what indicates high state of charge?
Specific gravity reading between 1.275 and 1.300.
What is considered to be the open-circuit voltage of a fully charged 12 cell lead-acid battery?
Approximately 26.4 volts. Or (12 x 2.2 volts) 28 volts are required for charging.
What is the open-circuit cell voltage of a NI-CAD battery?
1.25 volts.
What is a hazard when storing NI-CAD batteries and lead-acid batteries in the same area?
The fumes from one type can contaminate the electrolyte in the other type.
Can NI-CAD batteries be interchangeable with lead-acid types?
yes
How does a capacitor store electricity?
In the form of an electrostatic charge or field that exists between two conductors separated by an insulator.
What should be done when interchanging a NI-CAD battery with a lead-battery?
Clean, dried & neutralized with Boric acid or ammonia, then completely air/oven dried.
What is a probable cause when troubleshooting a NI-CAD battery for failing to deliver its rated capacity?
Faulty cells or cell imbalance.
What does LED stand for?
Light-emitting diode
