Defenitions Flashcards
Rectification is the process of converting DC voltage into AC voltage
True or false
False
Rectification is the process of converting AC voltage to DC voltage
The voltage drop of a centre tap full wave rectifier is
.7
1.4
2
1.5
.7
The voltage drop of a bridge rectifier is
.7
1.4
1.5
2
1.4
When a semiconductor made from silicone is heated, it’s resistance
Decreases
P type semiconductors are doped with elements that have
Two valence electrons
N type semiconductors are doped with elements that have
Five valence electrons
In N type semiconductor, the majority of current is conducted by
Electrons
In P type semiconductor, the majority of current is conducted by?
Holes
The outermost orbit of electrons is called the?
Valance shell
Atoms with nearly empty valence shells make good?
Conductors
Atoms with half full valance shells make good?
Semiconductors
Atoms with full valance shells are good?
Insulator
The atoms of a material used as a conductor generally contain how many valence electrons
1 or 2
The atoms of a material used as an insulator generally contain how many valence electrons?
7-8
The two most common materials used to produce semiconductor devices are what?
Silicone and germanium
What is a lattice structure?
A lot of structure is an ordered arrangement of atoms in the atomic structure of a material
How is a P type material made?
Add a material which has only three valence electrons to appear semiconductor material
How is an N type material made?
Add a material which has five valence electrons to a pure semiconductor material
Which type of semiconductor material can withstand the greatest amount of heat?
Silicone
All electronic components are formed from P & N type materials. What factors determine what kind of components will be formed.
The thickness and manner in which the P and N type materials are joined together, determine the components
Name 4 types of fixed resistors
Composition carbon
Metal film
Carbon film
Wirewound
What is the advantage of a metal film resistor over a carbon resistor?
Metal film resistors do not change their ohmic value with age
What is the advantage of a wire wound resistor?
Wire wound resistors have a higher power rating
Is 51,000 ohms a standard value for a 5% resistor?
Yes
What is a potentiometer?
A variable resistor used to control voltage
What electrical quantity such as voltage, current, resistance, or watt is the oscilloscope used to measure?
Voltage
What quantity is measured on the X axis of an oscilloscope?
Time
What quantity is measured on the Y axis of an an oscilloscope?
Amplitude of voltage
What is the beam Finder used for?
To show the position of the trace, if it’s off the display
Why should a bright spot not be left on display of an oscilloscope?
It will burn a spot on the face of the CRT
What is the function of the slope control?
It permits the oscilloscope to trigger on the positive or negative half of the wave form
What type of metre measures the voltage drop across a resistor to determine its resistance value
Digital ohmmeter
What function does a heat sink serve when it is attached to a component?
The heat sink increases the surface area of the component, which permits air to remove heat at a faster rate
Why should thermal compound be used when attaching a component to a heat sink?
It produces a good thermal bond between two components
How many elements of a semiconductor material are contained in a diode?
Two
If a dial is made of silicone, how many volts does it take to turn it on so that it will conduct current in forward direction?
.6 to .7
Must the voltage connected to an anode of a diode be positive or negative to make it forward biased?
Positive
What does the PIV rating on diode mean?
The amount of voltage it can hold off in reverse direction
How many layers of semiconductor material are diodes constructed with?
2
True or false
A junction dialled is designed to conduct current from the cathode terminal to the anode terminal ?
False
A Junction diet is designed to conduct current from the anode terminal to the cathode terminal
Forward voltage drop of silicon diode at room temperature is approximately what voltage?
.7
When the anode is positive with respect to the cathode, a diode is what biased?
Forward
When the cathode is positive with respect to the anode, a diode is what biased
Reverse
The maximum voltage a diode can block in the reverse direction is known as what
Peak inverse voltage (PIV)
The small amount of current flow through a diode in reverse buys is called?
Leakage current
The forward voltage drop of a single LED is in the range of 1.6 V to 4.2 V
True or false
True
When powered from a fixed voltage source, an LED requires a resistor in series true or false
True
What do the letters LED stand for?
Light emitting diode
If an LED is connected to an AC circuit, will the output voltage be AC or DC
DC
What is the average Ford voltage drop of an LED?
1.7 V
Is the resistance of a CAD cell greater in darkness or in light?
In darkness
What is a rectifier?
Device that changes AC voltage into DC voltage
What is the simplest type of rectifier?
Halfway rectifier
What type of single phase rectifier requires the use of a centre tapped transformer?
Full wave rectifier with two diodes
What type of single phase rectifier requires the use of four diodes?
A bridge rectifier
What is the most efficient type of single phase rectifier?
Full wave rectifier, 2 diodes
What type of three phase rectifier requires the use of a WYE-connected transformer with a centre tap?
Half wave
How many diets are required to construct a three phase, full wave rectifier?
6
Which type of rectifier has less ripple? A full wave, single phase rectifier or a half wave three phase rectifier?
Half wave three phase rectifier
