RJs GEN Codes Flashcards
What is the formula for power in a DC circuit?
Power = Voltage times Current
P = VI
What is the relationship between mechanical and electrical power?
1 horsepower = 746 watts
What is meant by true power in an AC circuit?
The product of the circuit voltage and the current that is in phase with this voltage.
In what units is true power expressed?
In watts.
What is meant by apparent power in an AC circuit?
The product of the circuit voltage and the circuit current, without reference to phase angle.
In what units is apparent power expressed?
In volt-amps.
What is meant by reactive power in an AC circuit?
The power consumed in the inductive and capacitive reactances in an AC circuit. Reactive power is also called wattless power.
In what units is reactive power expressed?
In volt-amps reactive (VAR), or kilovolt-amps reactive (KVAR).
What is meant by power factor in an AC circuit? (Ratio)
The ratio of true power to apparent power. It is also the ratio of circuit resistance to circuit impedance.
How many watts of power are consumed by a US horsepower, 24-volt DC motor that is 75% efficient?
Power consumed is the same as Power in, and 1 horsepower (hp) equals 746 watts.
Therefore, Power In = Power Out = 1 hp = 0.75 hp (746 W/hp) = 499 Watts
What is meant by the capacity rating of a lead acid battery?
The number of hours a battery can supply a given current.
What electrolyte is used in a lead-acid battery?
A mixture of sulfuric acid and water.
Does the specific gravity of the electrolyte in a lead-acid battery increase or decrease as the battery becomes discharged?
It decreases.
What is the specific gravity of a fully charged lead-acid battery?
Between 1.275 and 1.300.
How many cells are there in a 24-volt lead-acid battery?
12.
What is the range of temperatures of the electrolyte in a lead-acid battery that does not require a correction when measuring specific gravity?
Between 70° and 90°.
How do you treat a lead-acid battery compartment to protect it from corrosion?
Paint it with an asphallic (tar-base) paint or with a polyurethane enamel.
What is used to neutralize spilled electrolyte from a lead-acid battery?
A solution of sodium bicarbonate and water.
How high should the electrolyte level be in a properly serviced lead-acid battery?
Only up to the level of the indicator in the cell.
Why is the closed circuit voltage of a lead-acid battery lower than its open-circuit voltage?
Voltage is dropped across the internal resistance of the battery.
What gases are released when a lead-acid battery is being charged?
Hydrogen and oxygen.
What is the electrolyte used in a nickel-cadmium battery?
Potassium hydroxide and water.
Why is a hydrometer not used to measure the state of charge of a nickel-cadmium battery?
The electrolyte of a nickel-cadmium battery does not enter into the chemical changes that occur when the battery is charged or discharged; its specific gravity does not change appreciably.
How can you know that the aircrat drawing you are using is the most current version of the drawing?
revision block numbers/ recent drawing logs