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WorksheetsCET Section I-1
Total questions: 75
Worksheet time: 38mins
Name
Class
Date
1.
If the op-amp in the circuit of Figure 1-1 is working properly, the signal voltage at point X should be:
a)
0 V
b)
0.7 V
c)
9 V
d)
18 V
2.
If a unit under test appears to be dead, what is the first area that should be suspect?
a)
power supply
b)
output unit
c)
middle functional block
d)
none of the above
3.
What symptom would be observed if the feedback resistor on a non-inverting op-amp circuit opens?
a)
no observable symptom
b)
reduced output
c)
output only at positive and negative saturation
d)
an overheated op-amp chip
4.
Using the proper ohmmeter, resistance tests in both directions are performed across a silicon diode which has been removed from a circuit. Both tests indicate high resistance. What can be concluded?
a)
it is a good component
b)
the diode is shorted
c)
the diode is open
d)
no conclusions until a power test is performed
5.
What output should be seen in the circuit of Figure 1-2?
a)
high
b)
low
c)
pulsing
d)
high impedance
6.
What symptom would likely be observed when the emitter bypass capacitor opens on a common emitter amp?
a)
no symptom is observable
b)
reduced gain
c)
overheated transistor
d)
overheated emitter resistor
7.
What Vcc power supply voltage should be observed in TTL circuits?
a)
3 – 15 V
b)
5 V
c)
12 V
d)
+ / - 15 V
8.
What device is often used to protect systems from very fast, momentary, voltage spikes?
a)
zener
b)
SCR
c)
varistor
d)
varactor
9.
What is the DC output of a Class A amplifier designed for maximum DC compliance, with no signal applied, and powered by 12 volts?
a)
.7 V
b)
0 V
c)
12 V
d)
6 V
10.
What indication is seen when resistance testing a good fuse?
a)
very low resistance
b)
infinite resistance
c)
low resistance in one direction and high resistance in the other direction
d)
approximately 1000 ohms in both directions
11.
If a diode in a bridge rectifier opens, the observable symptom is:
a)
there is no observable symptom
b)
increased ripple/decreased DC output under load
c)
the remaining bridge diodes fail due to overload
d)
the primary fuse blows
12.
The primary frequency of a fully loaded switching power supply might be about:
a)
60 Hz
b)
120 Hz
c)
1K Hz
d)
70K Hz
13.
If a diode in a bridge rectifier shorts, the most likely observable symptom is:
a)
there is no observable symptom
b)
increased ripple/decreased DC output under load
c)
the remaining bridge diodes fail due to overload
d)
the primary fuse blows
14.
Which segments on a seven segment display should be lit to display the number seven?
a)
a, b, c
b)
c, d, e
c)
d, e, g
d)
e, f, g
15.
If 4 volts is applied to the non-inverting input and 3.5 volts is applied to the inverting input of a differential amplifier configured for a gain of 10, the output voltage is:
a)
.5 V
b)
5 V
c)
7.5 V
d)
37.50 V
16.
What logic probe indication should be viewed on the data lines of a normally operating microprocessor based system?
a)
high
b)
low
c)
pulsing
d)
tristated
17.
What is the frequency of the signal of Figure 1-3 if the time/division is set to 50 microseconds/division?
a)
2K Hz
b)
5K Hz
c)
20K Hz
d)
50K Hz
18.
Which instrument should always be used with the power disconnected in the circuit under test?
a)
voltmeter
b)
ohmmeter
c)
ammeter
d)
frequency counter
19.
An ohmmeter test across the anode-cathode (with the gate unconnected) of an out of circuit SCR shows low resistance in both directions. What would you conclude about the SCR?
a)
it is defective, probably shorted
b)
it is defective, probably open
c)
it is a good component
d)
no conclusions until a power test is performed
20.
A switching power supply should initially be tested:
a)
unloaded
b)
loaded
c)
at reduced input voltage
d)
at reduced input frequency
21.
Which of the following must a grounding wrist strap have?
a)
a static collector band liner
b)
a Velcro adjustable band
c)
a direct short to ground to drain charge
d)
a large resistance in series with the technician
22.
The indications shown on Figure 1-4 were obtained using a logic probe. What conclusion can be drawn from the indications?
a)
the circuit is functioning properly
b)
the circuit is probably functioning properly, but an oscilloscope test is needed to confirm this
c)
the circuit is not functioning properly
d)
the circuit is probably not functioning properly, but an oscilloscope test is needed to confirm this
23.
What resistance indication should be obtained when testing a functional diode with an analog multimeter having sufficient voltage at the terminals?
a)
low resistance in both directions
b)
high resistance in both directions
c)
high resistance in one and low resistance in the other direction
d)
no indication, since an analog meter generally won’t turn on a diode junction
24.
What potential should be placed on the gate of an SCR when performing a simple trigger test?
a)
positive
b)
negative
c)
alternating
d)
answer depends on whether an NPN or PNP SCR is used
25.
What logical level would be represented by an output of 1.5 volts in a TTL digital circuit?
a)
high
b)
low
c)
tristate
d)
1.5 volts is not a valid logic high or low
26.
What effect does increasing the base bias, making it more positive, have on the reading of meter M1?
a)
the current remains unchanged
b)
the current decreases
c)
the current increases
d)
M1 leads would need to be switched
27.
What should the impedance of meter M2 in the circuit of figure 1-5 be to obtain the least amount of loading?
a)
low impedance
b)
equal to the impedance of the emitter resistor
c)
equal to the dynamic impedance of the transistor
d)
high impedance
28.
How is the voltmeter connected to measure the voltage developed in a component?
a)
in series with the component
b)
in parallel with the component
c)
remove the component and replace it with the meter
d)
momentarily open the component and measure its voltage
29.
When using an ohmmeter to test an SCR, the SCR can often be fired by:
a)
momentarily shorting the gate to the cathode
b)
momentarily shorting the gate to the anode
c)
momentarily shorting the base to the cathode
d)
momentarily shorting the base to the emitter
30.
What indication should be seen when viewing a microprocessor’s clock signal with a logic probe?
a)
high
b)
low
c)
pulsing high and low
d)
tristate
31.
Which coupling technique would be used to view a 50 mV noise signal riding on top of a 12 volt DC level?
a)
grounded
b)
inverted
c)
DC
d)
AC
32.
Which of the following is not indicated by a logic probe?
a)
a voltage in the logic high region
b)
a voltage in the logic low region
c)
a voltage in the undefined region
d)
the magnitude of a voltage in the undefined region
33.
On which of the following instruments would the occasional presence of the signal in Figure 1-6 be the easiest to detect?
a)
logic probe
b)
oscilloscope
c)
voltmeter
d)
signature analyzer
34.
Which oscilloscope control determines the input voltage level required to start the sweep?
a)
trigger source
b)
trigger level
c)
volts/div
d)
vertical coupling control
35.
Which of the following instruments would be most suitable for analyzing a continuous 10M Hz signal?
a)
voltmeter
b)
oscilloscope
c)
logic probe
d)
logic analyzer
36.
Which of the following voltmeter input impedances provides for the least amount of circuit loading?
a)
1,000 ohms
b)
10,000 ohms
c)
1,000,000 ohms
d)
impedance doesn't determine loading
37.
You are using an oscilloscope with an X10 probe. Because of the probe you must:
a)
divide the frequency reading by 10
b)
multiply the frequency reading by 10
c)
divide the voltage reading by 10
d)
multiply the voltage reading by 10
38.
Observation of two low frequency signals, about 60 Hz, on a dual trace scope generally requires the use of the:
a)
triggered mode
b)
expanded mode
c)
alternate mode
d)
chopped mode
39.
The combined input impedance of an oscilloscope and a 10X probe is generally:
a)
very low
b)
very high
c)
adjustable with the triggering source control
d)
adjustable with the triggering level control
40.
The compensation adjustment of an oscilloscope probe is usually performed when displaying a:
a)
random noise signal
b)
white noise signal
c)
sine wave
d)
square wave
41.
Which of the following voltage levels represents a valid high in most TTL circuits?
a)
0.4 V
b)
0.8 V
c)
1.5 V
d)
2.4 V
42.
Which of the following SCR firing techniques produces the lowest RFI noise?
a)
phase firing
b)
zero crossing firing
c)
arc-over firing
d)
diac firing
43.
What function does the optocoupler serve in a solid state relay?
a)
isolation
b)
power switch
c)
fuse
d)
optocouplers aren’t found in solid state relays
44.
Which kind of memory retains its contents only as long as power is applied?
a)
EPROM
b)
EEPROM
c)
ROM
d)
RAM
45.
What is the output of the logic circuit of Figure 1-7?
a)
high
b)
low
c)
pulsing
d)
tristate
46.
What is the gain of the amplifier in Figure 1-8?
a)
1
b)
10
c)
11
d)
100
47.
What is the approximate output of the comparator of Figure 1-9?
a)
0 V
b)
2.0 V
c)
2.4 V
d)
9 V
48.
If the J input of a JK flip-flop is high and the K input is low, what is the level on the Q output after the next clock pulse?
a)
high
b)
low
c)
tristate
d)
the opposite of its pre-clock state
49.
If 100 mV is applied to the op-amp circuit of Figure 1-10, what output voltage is produced?
a)
1 mV
b)
10 mV
c)
100 mV
d)
1 V
50.
If the voltage applied to the inverting input of a comparator is less positive than that applied to the non-inverting input, what is the approximate output voltage?
a)
-Vs (the negative supply voltage)
b)
+Vs (the positive supply voltage)
c)
0 Volts
d)
the voltage level applied to the inverting input
51.
What is the relative size of the gate current required to fire an SCR and the anode load current when it is conducting?
a)
a small gate current and a large anode current
b)
a small gate current and a small anode current
c)
a large gate current and a small anode current
d)
a large gate current and a large anode current
52.
What polarity voltage (with respect to the cathode) is applied to the gate of an SCR to fire it?
a)
positive
b)
negative
c)
ground
d)
0 V
53.
If 18 volts is applied to the circuit of Figure 1-11, how much voltage would be normally measured across RI?
a)
0 V
b)
6 V
c)
12 V
d)
18 V
54.
Which lead of a TRIAC generally controls the triggering of the device?
a)
main terminal 1
b)
main terminal 2
c)
base
d)
gate
55.
How much voltage should be dropped across the emitter-base junction of a silicon NPN transistor connected in a common emitter circuit if the amp is biased for class A operation?
a)
0.9 V
b)
0.7 V
c)
0.3 V
d)
0.1 V
56.
If 0.5 volts peak-to-peak is applied to the input of the amplifier shown in Figure 1-12, what is the approximate output voltage?
a)
2.227 Vpp
b)
4.55 Vpp
c)
10.0 Vpp
d)
Cannot be determined without transistor data
57.
During normal operation, how is the base-emitter junction of a Class A amplifier biased?
a)
forward
b)
reverse
c)
grounded
d)
open
58.
About how much voltage would be dropped across a reverse biased silicon diode?
a)
0 V
b)
0.3 V
c)
0.7 V
d)
the source voltage
59.
Generally, how much opposition to current flow is offered by a conducting, forward biased PN junction silicon diode?
a)
infinite
b)
relatively large opposition
c)
relatively little opposition
d)
no opposition
60.
About how much voltage would be dropped across a forward biased silicon diode?
a)
0 V
b)
0.3 V
c)
0.7 V
d)
the source voltage
61.
What is the resonant frequency of the circuit of Figure 1-13?
a)
70.7 Hz
b)
707 Hz
c)
707K Hz
d)
800K Hz
62.
What is the impedance of the circuit of Figure 1-13?
a)
50 ohms
b)
75 ohms
c)
56 ohms
d)
25 ohms
63.
As the frequency of the AC signal applied to a capacitor is increased, how does its reactance change?
a)
it stays the same
b)
it decreases
c)
it increases
d)
reactance does not apply to capacitance
64.
What is the approximate inductive of a 10 mH inductor in a 3.58 MHz circuit?
a)
10K ohms
b)
35.8K ohms
c)
100K ohms
d)
225K ohms
65.
What is the effective (RMS) voltage of 1.0 volt peak-to-peak signal?
a)
2.0 V
b)
1.0 V
c)
0.707 V
d)
0.3535 V
66.
How much voltage is dropped across a 10K ohms resistor that is in series with a 20K ohms resistor, when 10 volts is applied to the series circuit?
a)
6.6 V
b)
5 V
c)
3.3 V
d)
2 V
67.
How much current is flowing through R3 of Figure 1-14?
a)
0.00025 A
b)
0.0005 A
c)
0.0010 A
d)
0.0050 A
68.
What is the voltage across R2 in the circuit of Figure 1-15?
a)
3.33 V
b)
5 V
c)
6.66 V
d)
10 V
69.
What is the current through R1 in the circuit of Figure 1-15?
a)
0.5 mA
b)
0.75 mA
c)
1.0 mA
d)
1.5 mA
70.
How does the current flowing through a resistor change if the voltage applied to it is doubled?
a)
it halves
b)
it doubles
c)
it remains the same
d)
the kind of circuit, series or parallel, must be known
71.
Which of the following represents an acceptable 2.2K ohms 10% tolerance resistor?
a)
1850 ohms
b)
1900 ohms
c)
2400 ohms
d)
2450 ohms
72.
What is the decimal equivalent of binary 110101?
a)
4
b)
31
c)
47
d)
53
73.
What is the peak voltage of a 2 volt effective (RMS) signal?
a)
2 V
b)
2.8 V
c)
4 V
d)
5.6 V
74.
Which of the following is equivalent to .2 milliamps?
a)
.02 A
b)
.002 A
c)
.0002 A
d)
.00002 A
75.
What is the frequency of a signal which has a cycle time of 100 microseconds?
a)
10 kHz
b)
100 kHz
c)
1000 kHz
d)
10 MHz
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