Download EC331.Sheet1 - Arab Academy for Science, Technology

Arab Academy for Science & Technology& Maritime Transport
College of Engineering & Technology
EC331: Electronics
Lecturer: Dr. Mohamed Hassan
Assistants: Eng. Fadi S. Ayad
Sheet (1)
Multiple choice Questions:
1. How many terminals a diode should have ?
a) 1
b) 2
c) 3
d) 4
2. What is the resistor value of an ideal diode in the region of conduction ?
a) 0
b) 5 k
c) Undefined
d) Infinity
3. What is the state of an ideal diode in the region of non-conduction?
a) An open circuit
b) A short circuit
c) Unpredictable
d) Undefined
4. The diode _____.
a) is the simplest of semiconductor devices
b) has characteristics that closely match those of a simple switch
c) is a two-terminal device
d) All of the above
5. The ideal diode is a(n) _____ circuit in the region of nonconduction.
a) open
b) short
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6.
Which of the following is an atom composed of?
a) Electrons
b) Protons
c) Neutrons
d) All of the above
7. How many orbiting electrons does the germanium atom have?
a) 4
b) 14
c) 32
d) 41
8. How many valence electrons does a silicon atom have?
a) 1
b) 2
c) 3
e) 4
9. One eV is equal to _____ J.
a) 6.02 × 1023
b) 1.6 × 10–19
answer
18
c) 6.25 × 10
d) 1.66 × 10–24
10. Which of the following elements is most frequently used for doping pure Ge or Si?
a) Boron
b) Gallium
c) Indium
d) All of the above
11. The diffused impurities with _____ valence electrons are called donor atoms.
a) 4
b) 3
c) 5
d) 0
12. In what state is a silicon diode if the voltage drop across it is about 0.7 V?
a) No bias
b) Forward bias
c) Reverse bias
d) Zener region
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13. What unit is used to represent the level of a diode forward current IF?
a) pA
b) nA
c) A
d) mA
14. Which of the following ratings is true?
a) Si diodes have higher PIV and narrower temperature ranges than Ge diodes.
b) Si diodes have higher PIV and wider temperature ranges than Ge diodes.
c) Si diodes have lower PIV and narrower temperature ranges than Ge diodes.
d) Si diodes have lower PIV and wider temperature ranges than Ge diodes.
15. It is not uncommon for a germanium diode with an Is in the order of 1–2 A at 25°C to have leakage
current of 0.1 mA at a temperature of 100°C.
a) True
b) False
16. Calculate static resistance RD of a diode having ID = 30 mA and VD = 0.75 V.
a) 25
b) 40
c) 0.04
d) 0.025
17. Calculate ID if RD = 30 and VD = 0.84 V.
a) 28 mA
b) 0.028 mA
c) 2.8 A
d) 280 A
18. Refer to Figure 1.29. Calculate the dynamic resistance rd of a diode having ID = 27.5 mA.
a) 0
b) 2
c) 5
d) 26
19. Determining rd to a high degree of accuracy from a characteristic curve is very accurate.
a) True
b) False
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20. The _____ diode model is employed most frequently in the analysis of electronic systems.
a) ideal device
b) simplified
c) piecewise-linear
21. Calculate the power dissipation of a diode having ID = 40 mA.
a) 28 mW
b) 28 W
c) 280 mW
d) Undefined
22. Which capacitor appears in the forward-bias region?
a) 4
b) 32
c) 40
d) 140
23. Which capacitor appears in the forward-bias region?
a) Diffusion
b) Transition
c) Depletion
d) None of the above
24. At what kind of operating frequency diffusion or transition is a capacitor represented in parallel
with the ideal diode?
a) Low frequency
b) Moderate frequency
c) Mid frequency
d) Very high frequency
25. What is the value of the transition capacitor for a silicon diode when VD = 0? (Choose the best
answer.)
a) 1 pF
b) 3 pF
c) 5 pF
d) 10 pF
26. Which of the following devices can check the condition of a semiconductor diode?
a) Digital display meter (DDM)
b) Multimeter
c) Curve tracer
d) All of the above
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27. What does a high resistance reading in both forward- and reverse-bias directions indicate?
a) A good diode
b) An open diode
c) A shorted diode
d) A defective ohmmeter
28. The condition of a semiconductor diode can be determined quickly using a _____.
a) DDM
b) VOM
c) curve tracer
d) Any of the above
29. Determine the nominal voltage for the Zener diode at a temperature of 120° C if the nominal
voltage is 5.1 volts at 25° C and the temperature coefficient is 0.05%/° C.
a) 4.6V
b) 4.86 V
c) 5.1 V
d) 5.34 V
30. Calculate the temperature coefficient in %/° C of a 10-V nominal Zener diode at 25° C if the nominal
voltage is 10.2 V at 100° C.
a) 0.0238
b) 0.0251
c) 0.0267
d) 0.0321
31. In which of the following color(s) is (are) LEDs presently available?
a) Yellow
b) White
c) Orange
d) All of the above
32. What is the maximum power rating for LEDs?
a) 150 mW
b) 500 mW
c) 1 W
d) 10 W
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33. In which of the following is the light intensity measured?
a) Candela
b) Efficacy
c) Flux
d) Illumination
34. What is the range of the operating voltage level for LEDs?
a) 5–12 mV
b) 1.7–3.3 V
c) 5–12 V
d) 20–25 V
35. In general, LEDs operate at voltage levels from _____ V to _____ V.
a) 1.0, 3.0
b) 1.7, 3.3
c) 0.5, 4.0
d) None of the above
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