Basic Electricity Flashcards
What law describes the most fundamental or basic relationship in an electrical circuit?
Ohm’s law
What are three elements of Ohm’s law?
Voltage, current, resistance
How would you write Ohm’s law as an equation?
E= I x R
A 24 volt lead acid battery has how many cells?
12 cells at 2 volts a piece
In DC circuit, what unit measures power?
Watts
If the resistance in a DC circuit remains the same but the voltage doubles, what happens to the amount of current flowing in the aircraft?
It also doubles
What three elements are required to form an electrical circuit?
A source, load, and conductor
What are the 3 DC electrical circuits
Series, parallel and series parallel
A fully charged lead acid battery has a specific gravity that varies between what two values?
1.275 and 1.3
You must apply a corrosion to the specific gravity reading of electrolyte of a lead-acid battery when the temperature is outside of what two values?
When temperature is less than 70 degrees Fahrenheit and more than 90 degrees Fahrenheit
What is the reason for have separate facilities for storing and servicing nick-cadmium and lead-acid batteries?
The electrolytes in the two types of batteries is opposite and the fumes from one type can contaminate the electrolyte of the other type.
The state of charge of a ni-cad battery cannot be determined by using a hydrometer to measure specific gravity of the electrolyte for what reason?
The specific gravity in a Ni-cad battery does not change that much
What principle advantage of AC current over DC current?
Power can be transmitted over long distance more efficiently and with smaller wires because the voltage can be easily increased on decreased by the transformer.
What are the three causes of opposition to current flow in an AC circuit?
Resistance, inductive reactance and capacitive reactance.
Define inductance.
It is voltage induced in a coil that opposes change in current
What component creates capacitance in AC circuits?
A capacitor
How does a capacitor store electricity?
stored in a electrostatic field
What property of an AC circuit is defined by the term “impedance”?
The total opposition to the current flow.
What are two reasons that might cause a nickel-cadmium battery to fail to deliver its rated capacity?
Faulty cells or cell imbalance
What electrical values are measured by typical multimeter?
Voltage, current , resistance
One kilowatt is equal to how many watts?
1,000 watts
What is the function of a capacitor
To store electrical energy
What are four sources of electrical power
Mechanical, magnetism, pressure, chemical, photoelectric and thermal
What is the unit of measurement of power in a DC circuit
P= I x E
In DC circuit what occurs when voltage is increased while resistance remains constant?
Current increases
What instrument is used to determine the specific gravity of electrolytes in a lead acid battery
Hydrometer
What is the relationship between mechanical and electrical power
1 horsepower = 746 watts
What is voltage
Electrical pressure
To measure voltage is the voltmeter placed in series or parallel with the source
Parallel
What is electrical current
Flow of electrons in a circuit
To measure current through a component is an ammeter placed in parallel or in series with the component
In series
What is used to measure electrical resistance and continuity
Ohmmeter
What is impedance
The sum of resistance, capacitive reactance and inductive reactance
What is electromagnetic induction
It is a transfer of electricity by a magnetic field
What should be the appropriate electrolyte level in a properly serviced battery
Only up to the level of the indicator in the cell
