Basic Electricity Flashcards
1 kW is equal to how many watts?
1000 watts
What is a common cause of damage to solid-state components and/or integrated circuits?
Electrostatic discharge from the human body during handling
Describe magnetism
An object properties which attract metallic substances
When the external magnetizing force is removed, what is the difference between permanent/temporary magnets?
Permanent magnets retain their magnetism, and temporary magnets rapidly lose their magnetism
What makes up an electrical circuit?
Source of electrical energy, a resistance, and a conductor
What law governs the basic study of electricity?
Ohms law
What are the basic elements of ohms law?
E Dash voltage, R Dash resistance, I – current
Which change occurs in a DC circuit when applied voltage is increased and resistance remains constant?
Current increases
Ohms law expressed as an equation
E= IxR, R= E/I, I= E/R
Scientifically, power is measured in
Watts
Common methods electrical energy can be produced
Pressure, chemical, thermal, sunlight
The law relevant to voltage law
Kirchhoff’s law
Three types of DC electrical circuits
Series, parallel, and series/parallel (complex)
Types of circuits aircraft mechanics encounter on aircraft?
A combination circuit, series-parallel
Compare AC & DC circuits in aircraft
DC flows constantly in one direction. AC has ability to change direction at or during regular intervals, is lighter weight, and its voltage can be stepped up and down by using a transformer.
How much voltage do most aircraft systems require for special equipment?
Most need 24 V, needs 400 Hz AC current
You must apply a correction to the specific gravity that varies between what two values?
When the temperature is less than 70°F or more than 90°F
The functions of a capacitor in an AC circuit
The store electricity
How is capacitance represented in an AC circuit
Buy a capacitor
How is inductance represented in an AC circuit
By a coil
Describe inductance
Inducted voltage - which is opposite in direction to the applied voltage
What properties of an AC circuit oppose any change in current?
Resistance, inductive reactance, and capacitive reactance
Describe impedance in an AC circuit?
The components delay or slow down the AC current or voltage due to their internal resistance
What is the common use of most multimeters?
Troubleshooting and measurement of voltage, resistance, current continuity, capacitance, and inductance
Describe short circuit
Low resistance path between two poles
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 read is connected towards a positive voltage source and negative Jack to the 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 a specific gravity of a fully charged lead acid battery, what indicates the high state of charge?
Specific of gravity of the 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 12×2.2 Volts which equals 28 Volts are required for charging.
What is the open circuit cell voltage of a NiCad battery?
1.25 Volts
What is a hazard when storing NiCad batteries and lead acid batteries in the same area?
The fumes from one type can contaminate the electrolyte and the other type
Can NiCad batteries be interchangeable with lead acid types?
Yes
How does a capacitor store electricity?
In the form of a electrostatic charge or field that exists between two conductors separated by an insulator
What should be done when interchanging a NiCad battery with a lead battery?
Clean, dry and neutralize with boric acid or ammonia, then completely air/oven dried
What is a probable cause when troubleshooting the NiCad battery for failing to deliver it’s rated capacity?
Faulty cells or cell imbalance
