Logical Questions
Electronic Devices
1. Determine the total discharge time for the capacitor in a clamper having C = 0.01
= 500 k .
a) 5 ms
b) 25 ms
c) 2.5 ms
F and R
d) 50 ms
2. Which element dictates the maximum level of source voltage?
a) VZ
above
b) IZM
c) IZ
d) None of the
3. What type of diode circuit is used to clip off portions of signal voltages above or below
certain levels?
a) clipper or limiter
b) clamper
c) IC voltage regulator
d) none of the above
4. Each diode in a center-tapped full-wave rectifier is ________ -biased and conducts for
________ of the input cycle.
a) forward, 90º
b) reverse, 180º
c) forward, 180º
d) reverse, 90º
5. What is the voltage measured from the negative terminal of C4 to the negative
terminal of the transformer?
a) –10 V
b) –20 V
c) 10 V
d) 20 V
6. The output frequency of a full-wave rectifier is ________ the input frequency.
a) one-half
b) equal to
c) twice
d) one-quarter
7. PIV is which of the following?
b) peak input voltage
c) peak immediate voltage
b) peak inverse voltage
d) positive input voltage
8. Determine the peak value of the current through the load resistor.
a) 2.325 mA
b) 5 mA
c) 1.25 mA
d) 0 mA
9. Determine the peak value of the output waveform.
a) 25 V
b) 15 V
c) –25 V
d) –15 V
10. In a regulated supply, what term describes how much change occurs in the output
voltage for a given change in the input voltage?
a) load regulation
b) voltage regulator
c) line regulation
d) ripple voltage
11. A short circuit has a ________ drop across its terminals, and the current is limited
only by the surrounding network.
a) 5 V
b) 0 V
c) 1 V
d) ∞
12. Determine the peak for both half cycles of the output waveform.
a) 16 V, –4 V
b) 16 V, 4 V
c) –16 V, 4 V
d) –16 V, –4 V
13. What is the peak inverse voltage across each diode in a voltage doubler?
b) 2Vm
a) Vm
c) 0.5Vm
d) 0.25Vm
14. What is the VRRM (PIV rating) for the 1N4001 rectifier diode?
a) 50 V
b) 100 V
c) 200 V
d) 400 V
15. What type of diode circuit is used to add or restore a dc level to an electrical signal?
a) Clipper or limiter
above
b) clamper
c) IC voltage regulator d) none of the
b) 0.7 mA
c) 3.393 mA
16. Determine ID2
a) 6.061 mA
d) 3.571 mA
17. What is the logic function of this circuit?
a) Positive logic AND gate
b) Positive logic OR gate
c) Negative logic AND gate
d) Negative logic OR gate
18. In a regulated supply, what term describes how much change occurs in the output
voltage over a certain range of load current values, from minimum to maximum
current?
a) line regulation
b) voltage regulator
c) current regulator
d) load regulation
19. Determine the average value of the current through the load resistor.
a) 2.5 mA
b) 0 mA
c) 1.37 mA
d) 1.479 mA
20. What best describes the circuit?
a) Full-wave rectifier
b) Half-wave rectifier
c) Clipper
d) Clamper
21. What is the PIV for each diode in a full-wave center-tapped rectifier? Note: Vp(out) =
peak output voltage.
a) Vp(out) – 0.7 V
0.7v
b) Vp(out) + 0.7 V
c) 2Vp(out) – 0.7 V
d) 2Vp(out) +
22. Determine ID2.
a) 29.40 mA
above
b) 30.30 mA
c) 14.70 mA
23. Determine the current level if E = 15 V and R = 3 k
a) 0mA
b) 4.76 mA
d) None of the
.
c) 5 mA
d) 5 A
24. Determine V2.
a) 3.201 V
b) 0 V
c) 4.3 V
d) 1.371 V
25. If the ac supply is 50 Hz, what will be the ripple frequency out of the full-wave
rectifier?
a) 50 Hz
b) 60 Hz
c) 100 Hz
d) 120 Hz
26. How many terminals do the 7800 series fixed positive voltage regulators have?
a) 2
b) 3
c) 4
d) 5
27. An open circuit can have any voltage across its terminals, but the current is
always
________.
a) 5 A
28.
c) 1 A
d) ∞
b) 29.40 mA
c) 14.70 mA
d) 14.09
Determine ID1.
a) 0mA
mA
29.
b) 0 A
Refer to the figure given below. Which diode arrangement will supply a negative
output voltage?
30. A silicon diode in a half-wave rectifier has a barrier potential of 0.7 V. This has
the effect of
a) reducing the peak output voltage by 0.7 V.
b) increasing the peak output voltage by 0.7 V.
c) reducing the peak input voltage by 0.7 V.
d) no effect.
31. What best describes the circuit?
a) Full-wave rectifier
b) Half-wave rectifier
c) Clipper
d) Clamper
c) RL = 6 k
d) None of the
32. Determine the value of the load resistor.
a) RL = 5 k
above
b) RL = 5.5 k
33. Use the information provided here to determine the value of I DQ.
a) 0 mA
b) 4.3 mA
c) 5 mA
d) 10 mA
34. If the ac supply is 60 Hz, what will be the ripple frequency out of the halfwave rectifier?
a) 30 Hz
b) 50 Hz
c) 60 Hz
d) 120 Hz
35. Calculate IL and IZ.
a) 2 mA, 0 mA
b) 4 mA, 2 mA
c) 2 mA, 2 mA d) 2 mA, 4 mA
36. In the operation of a half-wave rectifier with a capacitor-input filter, the ripple
factor can be lowered by ________ the value of the filter capacitor or
________ the load resistors.
a) decreasing, decreasing
b) decreasing, increasing
c) increasing, decreasing
d) increasing, increasing
37. Refer to the figure given below. The probable trouble, if any, indicated by
these voltages is
a) one of the diodes is open.
B) a diode is shorted.
C) an open transformer secondary.
d) the filter capacitor is shorted.
38. In a particular problem, which mode has the highest level of I DQ?
a) Ideal
b) Approximate equivalent
c) Exact mode using characteristic curve
d) None of the above
39. Which diode(s) has (have) a zero level current and voltage drop in the ideal
model?
a) Si
b) Ge
c) Both Si and Ge
d) Neither Si nor Ge
40. Determine Vo if E1 = E2 = 10 V.
a) 9.3 V
b) 10 V
c) –10 V
d) 0 V
41. The output frequency of a half-wave rectifier is ________ the input
frequency.
a) one-half
above
b) twice
c) equal to
d) none of the
42. A diode is in the "________" state if the current established by the applied
sources is such that its direction matches that of the arrow in the diode
symbol, and VD ≥ 0.7 V for Si and VD ≥ 0.3 V for Ge.
a) Off
b) on
c) neutral
d) quiescent
b) 1.893 mA
c) 2.036 mA
d) 2.143 mA
43. Determine ID.
a) 0 mA
44. What best describes the circuit?
a) Full-wave rectifier
b) Half-wave rectifier
c) Clipper
d) Clamper
45. In a voltage-multiplier circuit, the number of diodes is directly proportional to
the multiplicative voltage factor.
True
False
46. Rectifiers are commonly used in battery chargers.
True
False
47. List the categories of clippers.
a) Series
b) Parallel
c) Series and parallel
d) None of the above
48. A silicon diode has a voltage to ground of –117 V from the anode. The
voltage to ground from the cathode is –117.7 V. The diode is
a) open.
49.
A
a) shorted.
c) forward-biased.
d) reverse-biased.
Which diode arrangement will supply a positive output voltage?
b
c
d
50. What is the logic function of this circuit?
a) Positive logic AND gate
b) Positive logic OR gate
c) Negative logic AND gate
d) Negative logic OR gate
51. Determine the current through each diode if E1 = E2 = 0 V.
a) 4.65 mA
b) 9.3 mA
c) 18.6 mA
d) 0.7 mA
52. Refer to the figure given below. If the voltmeter across the transformer reads 0 V,
the probable trouble, if any, would be
a) one of the diodes is open.
b) a diode is shorted.
c) an open transformer secondary.
d) the filter capacitor is shorted.
53. The term bipolar reflects the fact that ________ and ________ participate in the
injection process into the oppositely polarized material.
a) holes, neutrons
b) holes, electrons
c) neutrons, electrons
d) None of
the above
54. In the saturation region the collector-base junction is ________-biased and the baseemitter junction is ________-biased for a transistor.
a) reverse, forward
b) forward, reverse
c) reverse, reverse
d)forward,
forward
55. The step function (per step) of a curve tracer reveals the scale for ________.
a) collector current IC
b) VCE voltage
c) base current IB
d) All of the above
56. The base current is the ________ of the emitter and collector currents.
a) Sum
b) difference
c) product
d) None of the above
57. The outer layers of a transistor are ________ the sandwiched layer.
a) much smaller than
b) the same as c) much larger than d) None of the above
58. Typical values of voltage amplification for the common-base configurations vary from
________ and the current gain is always ________ .
a) less than 1, 50 to 300
c) 50 to 300, less than 1
b) 50 to 300, larger than 1
d) larger than 1, 50 to 300
59. If a value of
is specified for a particular transistor configuration it will normally be used
for ________ calculations.
a) Ac
b) dc
c) ac and dc
d) None of the above
60. The level of ________ is determined and displayed by advanced digital meters if using
diode-testing mode.
a) VBE
b) IC
c) IB
d) IE
61. The doping of the sandwiched layer is ________ that of the outer layers.
a) considerably less than
c) considerably more than
b) the same as
d) None of the above
62. The lower doping level ________ the conductivity and ________ the resistivity of the
material.
a) increases, decreases
c) decreases, decreases
b) increases, increases
d) decreases, increases