1. Which of the following is sometimes used to obtain a regulated voltage?
A. Series-connected, forward-biased junction diodes
B. Parallel-connected impatt diodes
C. Forward-biased Varactor diodes
D. Series-connected, reverse biased Gunn diodes
2. Another name for a four-layer diode is a
A. tunnel
B. Shottky
C. Shockley
D. DIAC diode.
3. To perform a voltage test on a diode, you measure the forward voltage drop across the diode and
compare this value to the
A. resistance value of the diode.
B. current across the diode.
C. resistance of the current-limiting resistor.
D. expected junction voltage of the diode.
4. In a working diode, the junction voltage
A. always equals the external applied voltage.
B. must be greater than the applied voltage.
C. aids the flow of electrons.
D. opposes the flow of electrons.
5. The shape of the characteristic curve for a neon lamp is the same as the shape of a characteristic curve for a diode.
A. four-layer
B. zener
C. constant-current
D. three-layer
6. When performing circuit calculations, Ohm's law can't be used to
A. find the current when the voltage and the resistance are known.
B. find the current in a nonlinear circuit.
C. find the voltage when the current and the resistance are known.
D. find the current in a linear circuit.
7. Which of the following diodes is very heavily doped with impurity atoms to obtain a high energy level?
A. Tunnel diode
B. Gunn diode
C. Light-emitting diode
D. Varactor diode
8. To test whether a fuse is blown, you can connect a _______ with the fuse.
A. neon lamp in series
B. silicon rectifier in series
C. neon lamp in parallel
D. varactor diode in parallel
9. Which of the following devices can be used to make a low-power circuit control of a high-power circuit?
A. A zener diode
B. A constant-current diode
C. An optical coupler
D. A rectifier diode
10. Which of the following types of diodes is made to be used as a voltage regulator?
A. The signal diode
B. The zener diode
C. The four-layer diode
D. The three-layer diode
11. Which of the following types of diodes is operated with a reverse current?
A. IMPATT diode
B. Noise diode
C. Varactor
D. Rectifier
12. The pointed end of the triangle in a diode symbol always points in the direction of the
A. N-type material.
B. positive polarity of the applied voltage.
C. depletion region.
D. P-type material.
13. The P-type and N-type materials in a semiconductor diode
A. can be disassembled for repairs.
B. are held together because opposite poles attract.
C. are welded together.
D. are joined together in one crystal.
14. Which of the following elements is a semiconductor material used to make diodes?
A. Antimony
B. Germanium
C. Galena
D. Arsenic
15. Which diode operates on the principle that a high current through a semiconductor material produces
microwave oscillation?
A. Avalanche
B. Three-layer
C. Gunn
D. Laser
16. The triangle in a diode symbol points in the direction of
A. electron flow.
B. conventional current flow.
C. the P-type material.
D. the positive polarity of an applied voltage.
17. A particular type of diode is reverse-biased to produce avalanching. The amount of avalanching is controlled by an electric field. This type of diode is a/an
A. laser diode.
B. IMPATT diode.
C. DIAC.
D. avalanche diode.
18. If the forward current rating of a diode is 450 mA, the diode should never be used in a circuit where
A. a forward current of 0.3 A is expected.
B. the diode's junction voltage is 0.6 V.
C. a forward current of 300,000 microamperes is expected.
D. the expected forward current exceeds the diode's rated current.
19. The principle of heating a filament to obtain a movement of electrons is called
A. rectification.
B. avalanching.
C. thermionic emission.
D. oscillation.
End of exam
20. To dim a lamp, the ground side of the lamp socket is connected to the ground side of the plug through
a three-position switch, or the dim position of the switch connects the AC to the lamp through a _______
diode.
A. four-layer
B. three-layer
C. neon
D. rectifier