Basic Electricity Flashcards
- One Kilowatt is equal to how many watts?
1000 watts
What is a common cause of damage to solid-state components and/or integrated circuits?
Eletro-Static discharge (ESD) from the human body during handling
Describe magnetism.
An object properties which attracts metalic substances.
When the external magnetizing force is removed the difference between permanent/temporary magnets is?
Permanent magnets retain their magnetism. Temporary magnets rapidily lose magnetism.
What makes up an electrical circuit?
A sorce of electrical energy, a resistance(load) and conductors (wires)
What law governs the basic study of eletricity?
Ohm’s law.
What are the basic elements of Ohm’s law?
E- Voltage, R- Resistance , I- Current.
What change occurs in a D.C. circuit when applied voltage is increased & resistance remains constant?
Current increases.
Ohms Law expressed as an equation:
E= I x R, R= E/I, I= E/R
Scientifically, power is measured in?
Watts
Common methods electrical energy can be produced is ?
Pressure (Pizoelectric), Chemical(Battery), Thermal, Sun light
The law relevant to voltage law is?
Kirchoff’s Law
Three types of DC Electrical Circuits:
Series, Parallel, Series-Parallel
Types of circuits A&P ́s encounter on an aircraft:
A combination circuit, series-parallel.
Compare AC & DC circuits in aircraft:
DC flows constantly in one direction. AC has the abillity to change direction at or during regular intervals, is lighter in weight and it ́s voltage can be stepped up and down by using a transformer.
How much voltage do most aircraft systems require for special equipment?
Most 24 volts, needs 400Hz AC current.
You must apply a correction to the specific gavity that varies between what two values?
When the temperature is less than 70°F or more than 90°F.
How is capacitance represented in an AC circuit?
By a Capacitor.
The function of a capacitor in an AC circuit:
To store electricity
How is inductance represented in an AC circuit?
By a coil
Describe inductance
Inducted voltage which opposite in direction to the applied voltage.
Properties of an AC circuit which opposes any change in 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 ammeter or multimeter in series by opening or breaking the circuit. The positive side of the meter (RED) is connected towards the positive voltage source. Negative jack (BLACK).
Why would you not perform a specific gravity check of electrolyte NI-CAD battery?
Because 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 (BATTERY LIQUID) between 1.275 and 1.310.
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 eletricity?
In the form of an eletrostatic 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.
