K Flashcards
What electrical component is used to convert alternating current to pulsating direct current?
diode
A diode allows current to flow in one direction, converting AC to DC.
What are the two most common materials used as the base material in semiconductor components?
- Silicon
- Germanium
Silicon is the most widely used semiconductor material.
What is the polarity of a diode’s anode?
+
The anode is the positive side of the diode.
What is the polarity of a diode’s cathode?
The cathode is the negative side of the diode.
What polarities should a diode be connected to in a circuit in order for the diode to conduct electrical current?
Anode- +
Cathode- -
This configuration allows current to flow through the diode.
What is it called when a diode is connected into an electrical circuit so it will conduct current?
Forward bias
Forward bias occurs when the anode is more positive than the cathode.
What polarities should a diode be connected to in a circuit in order for the diode to block electrical current?
Anode- -
Cathode- +
This configuration prevents current from flowing through the diode.
What is it called when a diode is connected into an electrical circuit so it will block current?
Reverse bias
Reverse bias occurs when the anode is less positive than the cathode.
What is another name for a diode?
rectifier
A rectifier converts AC voltage to DC voltage.
If you connect the red lead of an ohmmeter to the anode of a diode and the black lead to the cathode, what should the meter read?
0
This indicates that the diode is functioning properly in forward bias.
If you connect the red lead of an ohmmeter to the cathode of a diode and the black lead to the anode, what should the meter read?
O.L
This indicates that the diode is blocking current in reverse bias.
What is the problem with the diode if the ohmmeter reads very low or zero resistance in both directions?
short circuit
This indicates that the diode is faulty and not functioning properly.
What is the problem with the diode if the ohmmeter reads very high or infinite resistance in both directions?
Open
What are Zener diodes most often used for an electronic circuit?
Voltage regulator
What is special about an LED that is not true about other DIODES?
Emits light
Name the diode type shown below and label the annoyed and cathode
> z
Type
Zenner
Cathode left anode right
What polarity should an NPN transistor be connected to a circuit in order for the transistor to allow electrical current from emitter to collector?
Base +. Emitter -
What priorities should a PNP transistor be connected to a circuit in order for the transistor to allow electrical current from emitter to collector?
Base - Emitter +
What is the problem with the transistor if an ohmmeter reads very high resistance between the collector and emitter even when the proper priorities are connected between base and emitter?
Open
What is the problem with a transistor if an ohmmeter reads very low resistance between the collector and emitter regardless of what priorities are connected to the base and emitter?
Short
What point in the circuit is considered to be a zero voltage reference?
Ground
What type of circuit fault is characterized by a break in the circuit?
Open
What type of circuit fault is characterized by current bypassing all or some of the electrical load in the circuit?
Short
What type of circuit fault is characterized by there being a voltage drop where there shouldn’t be a voltage drop?
Added resistance
If there is system voltage across two points and there are no other voltage drops in the circuit what type of fault does that indicate?
Open
If the voltmeter is placed across light in a circuit, what should the voltameter indicate if the power switches open?
0
If volt meter is placed across a circuit breaker or a fuse and it reads 0 V ,what is the condition of the circuit breaker/ fuse?
Good
If a Volta meter is placed across a switch and it reads system voltage ,what position is the switch in?
Open
If a voltmeter is placed across the circuit breaker or fuse and it reads system voltage, what is the condition on the circuit breaker/fuse?
Bad
If an ohmmeter is placed across a lightbulb, and it is isolated from the rest of the circuit. What will the ohmmeter indicate?
The light bulb’s resistance
_o _
Lamp
-o/o_
Switch
-._
Push To test light
. ✓ .
Fuse
