Electricity 2 Flashcards
What is a battery?
A device that converts chemical energy into electrical energy.
Name the two types of cells of a battery?
Primary Cells
Secondary Cells
What would the hydrometer reading be for a fully charged Lead Acid Battery?
1.275 - 1.300
During an installation of a battery into an aircraft, when should the negative terminal be connected?
After the positive
What is “deep cycling” or equalization of a battery?
Removes the memory of a nicad battery
What will a measured discharge test tell the mechanic?
State of Charge
How do you check the state of charge for a lead acid battery?
Measured Discharge Test
What happens to the electrolyte in a lead acid battery during discharge?
More susceptible to freezing
What is used to check specific gravity of a lead acid battery?
Hydrometer
How many volts per cell are in a NiCad Battery?
Between 1.55 & 1.80
How many volts per cell are in a lead acid battery?
2.1
What are two ratings found on aircraft battery?
Voltage & Amp Hour Capacity
What is used to neutralize a NiCad battery’s Electrolyte?
Baking Soda & Water
What is used to neutralize a lead acid battery’s electrolyte?
Bicarbonate / Baking Soda
If batteries are connected in parallel with each other, what increases?
AMPS
What three factors affect the capacitance of a capacitor?
The Size of the Conductor
The Size of the Gap Between Them
The Dielectric
What letter is used to represent capacitance?
C
How does a capacitor store electrical energy?
In the electric field between opposingly charged plates.
Transformers work off of what electrical principle?
Electromagnetic Induction
What happens to inductive reactance if frequency is increased?
Short Circuit
Inductance = ?
Lags
Capacitance = ?
Leads
How many cells does a 12-Volt lead acid battery have if the cells are connected in series?
6
What is the number of cycles per second in an AC circuit called?
Frequency
Inductance opposes the change in current by the generation of what?
Counter Electromotive Force
If you measure the voltage at an AC house hold outlet on your multi-meter you’re reading what value?
Effective Value
What is the power factor of a purely resistive AC circuit?
1
What is the power factor of a purely inductive circuit?
0
In an AC circuit the effective value for voltage is what?
Less than peak
What 3 things must be present in order to have electromagnetic induction to occur in a generator?
Conductor, Magnetic Field, And Relative Motion between the two
How many degrees out of phase are each phase in a 3-Phase generator?
120
When you have different rated inductors connected in series, what would the total inductance be?
Equal to the sum of all inductors
The opposition to the flow of alternating current caused by a coil is called what?
Inductive Reactance
What frequency of alternating current is most commonly used on an aircraft?
400
In an inductive circuit the current will either lead, lag, or equal the voltage?
Lags the Voltage
What are not one of the two ways to connect a 3-phase generator?
a) TRIAC
b) Y
c) Delta
TRIAC is not a way
What happens to current in a set up transformer with a ratio of 1:8
Current is reduced 8 times
You have different rated capacitors connected in series what would your total capacitance be?
Less than the capacitance of the lowest rated capacitor
What should the working voltage rating of the capacitor installed in an AC circuit be?
50% greater than the highest applied voltage
In a capacitance circuit the current will either lead, lag or equal?
Lead
What effect does increase either frequency or capacitance have on a capacitive reactance?
Inversely Proportionate
What type of capacitors can be safely installed in an AC circuit?
Non-Electrolytic
Self-Healing capacitors during closed and metal containers filled with what?
Oil Dielectric
What is the formula of times constant with the capacitor circuit?
R*C
What does a diode block in an AC circuit?
Current
What does a rectifier convert in a circuit?
AC to DC
The term forward bias means that the diode is what?
Conducting current flow
When calculating power in a reactive or inductive AC circuit the true power is?
Less than apparent power
When a reactive effects of a capacitor and an inductor are equal the circuit is said to be what?
Resonate
What is the total opposition to the flow of current in an AC circuit?
Impedance
