A-6 Electrical ASE Test Preparation     


Semiconductors & Logic Gates

1. Technician “A” says a diode is used to control the direction of current flow. Technician “B” says a diode is used to control a voltage spike across an inductor. Who is correct?

A only.
B only.
both A and B.
neither A nor B

 

2. The voltage drop across a silicon semiconductor is:

5v - 7v .
0.5v - 0.7v .
0.05v - 0.07v.
50mv - 70mv .

 

3. What will a Zener diode do at breakdown voltage (avalanche point)?

allow reverse current to flow.
stop the flow of reverse current.
sustain damage as a result of current overload.
stop the flow of either forward or reverse current.

 

4. Technician A say the diode shown in the schematic circuit below is reverse-bias. Technician B says that, in this circuit, the light would be OFF. Who is correct?

technician A only.
technician B only.
both technician A and technician B.
neither technician A and technician B.

 

5. A transistor:

is similar to a relay in that it uses a small amount of current to control a larger amount of current flow
has three connections called the base, emitter, and collector.
is like a switch in that it is used to turn a circuit on and off.
all of the above.

 

6. Technician A says that a diode that is forward-biased acts like a closed switch. Technician B says the anode lead of the diode must be connected to the positive side of the voltage source for the diode to be forward-biased. Who is correct?

technician A only.
technician B only.
both technician A and technician B.
neither technician A and technician B.

 

7. When checking a diode with a D.V.O.M. set to Diode Check, a good diode would show:

a reading of 0.5-0.7 volts in both directions.
a reading of ‘OL’ in both directions.
a reading of 0.0 volts in both directions.
a reading of ‘OL’ in the one direction and a reading of 0.5-0.7 volts in the other.

 

8. In the transistor is shown below, what type of electrical signal is used to energize the base:

either positive (B+) or negative (-) because it is a bidirectional transistor.
positive (B+) because it is a NPN.
negative (-) because it is a PNP.
light, because it is a photo transistor.

 

9. The arrow in the transistor indicates:

the NPN type of transistor.
which side the electrical load is placed in the circuit.
the direction of positive current flow as it flows to ground.
the collector circuit.

 

1O. What type of transistor is shown below:

JPET.
Darlington pair.
NPN Bi-polar.
PNP Bi-polar.

 

11. Field-effect transistors operate:

on the same principle as magnetic field devices.
with a small input voltage and current.
with a small input voltage but practically no input current.
ith high input current.

  

12. Technician A says bipolar transistors have the same basic operating characteristics as field effect transistors. Technician B says that bipolar and field-effect transistors are complimentary, which means they both operate in exactly the same manner except all voltage polarities are reversed. Who is correct?:

technician A only.
technician B only.
both Technician A and Technician B.
neither Technician A or Technician B.

 

13. A bipolar transistor circuit is operated so that

a small change in base current controls a large change in collector current.
a small change in collector current controls a large change in base current.
a small change in collector current controls a large change in emitter current.
a small change in emitter current controls a large change in collector current.

 

14. The three terminals on a transistor are

Base, ground and collector.
Emitter, ground and collector.
Base, emmiter and collector.
Drain, case and emitter.

 

15. The electrical symbol illustrated below represents a:

OR gate.
AND gate.
NOR Gate.
NAND Gate.

 

16. The electrical symbol illustrated below represents a:

OR gate.
OP-AMP.
NOR Gate.
NOT Gate.

 

17. The electrical symbol illustrated below represents an:

OR gate.
OP-AMP.
NOR Gate.
NOT Gate.

 

18. For the electrical symbol illustrated below to represent "0" as it's output, the inputs must be:

one input "on" the other "off".
both inputs "on".
both inputs "off".
first input "off" the second "on".

 

19. For the electrical symbol illustrated below to represent "0" as it's output, the inputs must be:

one input "1" the other "0".
both inputs "1".
both inputs "0".
the top input "0", the bottom input "1".

 

20. For the electrical symbol illustrated below to represent "1" as it's output, the inputs must be:

one input "1" the other "0".
both inputs "1".
both inputs "0".
the top input "0", the bottom input "1"..

 

21. In order for output 'Y' to be a"1", inputs A, B, and C must be:

A=1, B=0, C=0.
A=0, B=0, C=0.
A=1, B=0, C=1.
A=0, B=1, C=0.

 

22. The voltage drop across an L.E.D. (Light Emiting Diode) is:

5v - 7v.
0.5v - 0.7v.
1.5v - 2.2v.
0.2mv - 70mv.

 

23. The two junctions of a bipolar transistor are checked for proper operation using the DIODE test setting on the digital multimeter. Technician A says the reading from base to emitter should be about 0.6 volts in one direction and an over-range reading in the other direction. Technician B says the reading from base to collector should be over-range or open in both directions. Who is correct?:

technician A only.
technician B only.
both Technician A and Technician B.
neither Technician A nor Technician B.

 

24. Technician A says that LED-1 will be ON and LED-2 will be OFF when the circuit is connected as shown below. Technician B says that both LED-1 and LED-2 will be ON when the circuit is connected as shown below. Who is correct? :

technician A only.
technician B only.
both Technician A and Technician B.
neither Technician A nor Technician B.

  

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