Final Test Cards Flashcards
How does a Zener diode work
Has to be reverse bias
And have a lower voltage then the source
List 6 method used to produce electricity
Piezoe electric -pressure
Tribo electric- friction
Photo voltaic - light
Magneto electric- magnetism
Thermol electric- heat
Electro chemical- chemical
How many electrons would you find in the following valence shells?
Semi conductor
Conductor
Insulator
Semi conductor - 4
Conductor 1-3
Insulator 5-8
What is meant by the term line drop?
Voltage drop caused by resistance in the conductor
What is meant by the term line loss?
Power loss caused by resistance of the conducter
Explain Kirchoff’s current law?
Current in equals current out
Explain Kirchoff voltage law
Algebraic sum of all voltages in a close loop is equal to zero 
List 3 forms of ohms law
E=IR
I=E/R
R=E/I
List 3 forms of power loss
P=IE
P=I2•R
P=E2•R
Volts are the flow of electrons
true or false
False
List 3 advantages of Edison 3 wire circuits
1 ( Less conductor material is required )
2 ( 2 different voltages available )
3 (less line loss, greater efficiency)
List 4 factors that affect the resistance of a conductor
Length
Diameter
Temperature
Material
What’s bigger a circular mil or a square mil
Square mill is bigger
Why should the nutral of an Edison 3 wire circuit never be opened
Alters voltage and current in the circuit if it’s unbalanced
List 5 characteristics of magnetic lines of force
Posses direction
Complete loops
Tension along there lines = smaller
Repel each other
Cannot intersect or cross
Witch types of diagrams are most use by electrocutions
Schematic / Wiring
List three reasons for meter reading errors
1) Meter position
2) Temperature/ humidity
3) Meter leading
What is the ideal resistance for an ammeter
And voltmeter
Ammeter = low
Voltmeter = high
What is the ideal resistance of a ammeter and voltmeter
Ammeter = low
Voltmeter = high
What is meter loading
When a meter is added to a circuit and alters the voltage or current significantly
What are the laws of charged bodies
Like charges repel, opposites attract
What are the two most common semi conductor material used
Silicon or geranium
What types of charge is associated with N type and P type material
N= negative
P= positive
Do semi conductors have a negative or positive temperature coefficient
What does it mean
Negative
It means Temp will increase and Resistance will decrease
How is heat dissipated from a semi conductor device such as a diode
Use a heat sink
Do semi conductor have a negative or positive temperature coefficients
Negative
Because T increases, R decreases
How is heat dissipated from a semi conductor device such as a diode
Uses a heat sink
What is meant by the frame forward bias and reverse bias
Forward bias = current flows in the forward direction
Reverse bias = reduces current flow in diodes
Why is the PIV rating of a diode important to no
So you don’t go higher then it or the diode will be forced to conduct in reverse bias
Why is the PIV rating of a diode important to no
So you don’t go higher then it or the diode will be forced to conduct in reverse bias
What is a common application for a diode for inductive loads
Freewheeling diode
What are two topical ratings that come with Zener diodes
1) Zener voltage
2) Watt rating
Can Zener diodes always be tested with and ohmmeter
Most of the time
If provided the reverse bias break over voltage isn’t breached
What happens to the depletion region when a diode is connected forward bias or reverse bias
Depletion zone is reduced
List two types of damage that can occur from and electrical fault
Mechanical, heat damage
What hight should you not enter a ditch
1.2 meters
