1. A PLC that drives a DC circuit most often uses what kind of output device?
A. DC motor
B. AC motor
2. Speakers on a large PA system (severa! hundred feet of wiring), using a central amplifying
system, should be connected using:
A. a 70 volt system.
B. impedance matching devices at each speaker.
C. four-phase inversion.
D. DB-9 connectors.
3. This figure represents which of the following-answers?
A. Closed-loop motor speed control
B. Open-loop motor speed control
C. A mechanical adder
D. A damped motor-generator set
4. Input impedance in a central amplifying system should be _____ ,
5. In a three phase, ungrounded, Delta connected transformar, what is !he relationship between
phase voltage and line voltage?
A. Phase voltage equals line curren! minus 1.732
, B. Phase voltage equals line voltage divided by kilowatts
C. Phase voltage equals line voltage
D. Phase voltage equals line voltage times 1.732
6. A check of the curren! on L 1, L2 and L3 in a three-phase motor rated at 15 amps should show:
A. 1a, 2a, 3a.
s: 10a, 10a, 10a.
C. 5a, 10a, 15a.
D. 15a, 5a, 15a.
7. The voltage drop across a conductlng SCR would be __ _
A. .7 V
C .. 07V
8. "ESO", regarding MOS equipment, means:
A. Electronic Semiconductor Device.
B. Enhanced Storage Design.
C. Extended Standard Decoder.
D, Electrostatic Discharge,
9. The time required for a PLC to process input information and to respond is called ___ _
1 O. Name the three types of lnsulation Resistan ce Measurements.
A. voltage, continuity, frequency
B. continuity, volts and amps
C. spot time testing, Polarization lndex, Step Voltage
D. voltage, time testing and frequency testing
11. Which of these instruments would not be used for testing AC or DC circuitry?
12. You have a 500V 50HP DC motor. lgnoring losses, about how much curren! would you expect
the motor to draw when it is fully loaded?
13. In the following figure, the circuit is a:
B. Low-pass filter.
D. High-pass filler. IN A -=---vv--+-1!--'-
14. 1 horsepower (HP) is equal to how many watts?
K ::¡:4 70pf
15. To assure the same accuracy at both 100 Hz and 100 MHz, the signa! level into a frequency
counter must be:
A. higher at 100 MHz.
B. higher at 100 Hz.
C. inductively coupled at 100 MHz and capacitívely coupled at 100 Hz.
D. resistively coupled at 100 MHz and direct coupled at 100 Hz.
16. The use of an X-Ray gauge using a non-radioactiva source to measure the thickness of a
material is regulated by:
C. ISO 9000
Compared to an analog meter, which of these would NOT be considerad an advantage of a DMM
B. less chance of reading error
C. better accuracy
D. automatic polarity indication and ranging
The armature core of .a rotor is constructed of thin laminated steel sheets insulated from each
other to provide low reluctance (magnetic resistan ce) between the magnetic field poi es. The core
is laminated to reduce circular moving currents which are called:
A. web curren!.
B. eddy curren!.
C. polarizing curren!.
D. reciprocating curren!.
Which of these is considerad the mínimum AC current lethal to humans?
A. 10 ma ··
B .. 005 ma
C. 100 ma
D. 500 ma
In the following figure, motor A fails to run. The measurement across M is zero V AC. Across
FIELD is zero V DC. Across F is 115 V AC. One of the below is open causing the problem. Which
You must replace a fuse in a motor circuit. The drawings call for a 480V, 10A fuse, but you have
none. Which of these would be your best substituta?
A. 100v, 15A
B. 200v, 11A
C. 400v, 5A
D. 500v, 8A
Which one of the following deséribes the data transfer method being used between blocks in the
following PC diagram? •
B. Bus CPU RAM
C. Novel! 1 1 1
D. Multiplex 1 1
23. 1 meter is equal to how many feet?
D. 3.28 fVs
24. Synchro-transmitters function primarily as:
A. mechanical input-mechanical output devices.
B. mechanical input-electrical output devices.
C. amplification devices.
D. phase detectors.
25. One of !he unique properties of CMOS components is their ability to work with a very wide range
of power supply voltages. This would be _____ _
A. -3 to -15v.
B. +6 to +21 v.
C. +3 to +15v.
D. +4.5 to +24v.
26. In the following figure, the circuit is a _____ _
B. low-pass filler
C. bandpass filler
D. high-pass filler
.02uF .01uFI llOk
27. Which one of !he below components is most easily damaged by static discharge?
28. What is an advantage of utilizing a DC motor versus an AC motor?
A. Smaller in size far equivalent horsepower rating
B. Shock hazards are nonexistent
C. Simplistic speed control
D. Less overall maintenance required
29. What is !he resistance of 2000 ft. of #1 O AWG wire?
A. 10 ohms
B. 1 ohm
C. 2 ohms
D. 20 ohms
30. An opto-isolator would be used in industrial applications to:
A. shield the are of a welder.
B. provide an interface between a limit switch on an AC circuit anda salid state logic circuit.
C. remotely observe machinery in operation.
D. filler out specific light frequencies far use in chemical processes.
31. Which statement is NOT true of a silicon controlled rectifier?
A. has five layers of semiconductor material
B. is used as a semiconductor switch
C. has three terminals
D. curren! flows in only one direction
32. A/An ~--- section of a PLC reads all input values and decides which outputs are to be deenergized
A output table
B. input module
C. memory bank
33. You have a problem with a new multi-conductor cable you just installed. You are certain that you
have lost continuity in one of the conductors or connections. How could you check for
continuity without deinstalling the cable?
A one at a time, jum per the leads on one end to a common return or one other selected lead. Check at
other end for continuity from the return to that one and no continuity to ali other leads.
B. disconnect ali leads and check for low resistance to a common ground
C. connect a battery to !he shell and use a trouble light to check for light on each conductor
D. short ali !he leads on one end together. Disconnect one ata time and while checking from the other
end for open connections on ali !he leads
34. The difference between the "feedback" signa! and the "set-point" signa! in a typlcal process
control system is callad the ____ signa!.
35. A multiplexer might also be referred to as a/an: _____ _
C. data selector
D. data distributor
36. A Printed Armature, ora Surface-wound Armature motor, are designs for _______ .
A DC servo motors
B. DC drive pump motors
C. high-efficiency AC motors
D. amplidyne rotational amplifiers
37. 460V AC is considerad ____ _
A low voltage
B. medium voltage
C. high voltage
D. ultra-high voltage
38. In determining wire size or diameter, the insulation thickness is included.
39. Which one of the below is a coiled, non-circular tube used to measure pressure?
A Bourdon tube
What is the advantage of utilizing a 3-phase versus a single-phase AC motor?
A Easier availability of repair parts
B. Smaller physical size for same horsepower rating
C. 3-phase power is readily available
D. 3-phase motor is less likely to overheat
41. Which one of the below has most commonly replaced incandescent lamps as the light source for
C. sodium vapor
42. Which of these instruments does not require direct contact with the circuit being tested?
A. VTVM - vacuum tube voltmeter
D. DMM - digital multimeter
43. The characteristic impedance of RG59U coaxial cable used in CATV and MATV systems is:
A. 50 ohms
B. 75 ohms
C. 100 ohms
D. 300 ohms
44. What is the synchronous speed of a 4-pole 3-phase induction motor?
A. 1800 rpm
B. 2400 rpm
C. 3600 rpm
D. 4500 rpm
45. The nameplate voltage on a three phase induction motor says 460V. The power source you wire
the motor to should meas u re _____________ _
A. 460VDC between source and ground
B. 460VAC between source and ground
C. 460VDC between two source wires
D. 460VAC between two so urce wires
46. The crowbar circuit associated with power supplies may be designed to:
A. blow the power fuse or circuit breaker if the power supply exceeds a preset voltage.
B. prevent the power fuse or circuit breaker from opening if power supply output voltage is exceeded.
C. continue supplying power should the bridge rectifier become defective.
D. take the place of the zener rectifier diode should the zener avalanche.
47. The 1/0 address used with a PLC defines the ___ of a device.
B. data capability
48. Which of these is considerad to be a characteristic of an IDEAL op-amp?
A. very high frequency response
B. very high gain
C. Ov output for a O volt differential input
D. very high input impedance
49. How would you reverse the direction of rotation of a 3-phase AC motor?
A. replace the supply fuses with larger ones
B. swap two of the three leads
C. rearrange ali the connections
D. tie one lead to the case of the motor
An "exclusive OR" gate will produce a high(1) output if:
A. ali inputs are 1 's.
B. only one of the inputs is 1.
C. multiple, but not ali, inputs are 1 's.
D. ali inputs are O's.
Which one of these would not be found in an IC chip?
The ampacity of a wlre is riot the same as its current-carrying ability.
A zero-volt logic level is also referred to as _____ .
A. O, high, true
B. 1, high, true
C. O, low, false
D. 1, low, false
Which of these is NOT true regarding 3-phase power?
A. it delivers constant power as opposed to the pulsating power delivered by single phase
B. it makes motor design simpler
C. it is initialiy more expensive than single phase to deliver the same power because of the extra
D. you can use just 2 of the 3 phase wires to supply your single-phase needs
Which of the following best describes the logically "active" state of the circuit shown in this
diagram (producing a low or zero output)?
A. A or B = O and C=O
B. A and B = 1 or C = 1
C. A or B.= 1 and C = o
D. A = 1 and B and C = O 8
In the following figure, the circuit is ª~-----
B. low-pass filter
C. bandpass filter D. high-pass fil ter "
A 2000 ft length of #1 O AWG copper wire carrying 18 amps of curren! will drop __ volts.
Which formula will provide !he shaft RPM for a synchonous motor?
A. RPM=60 X applied AC frequeney/number of pales
B. RPM=50 X applied AC frequeney/number of pole pairs
C. RPM=50 X applied AC frequeney/number of pales
D. RPM=60 X applied AC frequency/number of pole pairs
Name the three types of magnetic controller configurations.
What is !he minimum forward-to-reverse resistance ratio for silicon signal transistors?
The field curren! used to excite an AC generator mus! be DC.
Triacs are most commonly used to _____ _
A. rectify AC
B. regulate power
C. protect against power surges
D. turn AC circuits on and off
What should be done to reverse the direction a three-phase 220/440 motor runs?
A. swap L 1 and insulate
B. short L 1 and L3 together
C. swap any two line conneetions
D. reconfigure connections far higher voltage
What is !he purpose of a PLC 'watch dog' circuit?
A. maintains PLC output voltages even if sean is not eompleted
B. assures unauthorized personnel do not !amper with settings
C. shuts down the unit if the sean is no! eompleted
D. fills in any gaps in the sean or output by averaging
Using the following figure, F-D is a thermostat, D-E a limit switch, and G-E a heating coi!. The
heat cycles on and off and B-C measures 120VAC, but !he fan does no! run. Which one of !he
following is probably defective?
A. A-B relay A
B. Thermostat ,-----
L1 _ ____.._
UNE t.. ------J L2 INPUT E
Which of these is true relating to a common-collector transistor configuration?
A low input resistance
B. high curren! gain
C. high voltage gain
D. high output resistance
A very basic "Strain Gauge" uses which one of the following principies?
You have a 460V 3-phase 50 HP induction motor. lgnoring losses, about how much curren!
would you expect the motor to draw when it is fully loaded? __ amps.
Which of the following components is leas! likely to fail?
A lntegrated circuí!
B. a device that is running hot
C. a small signa! transistor
D. high power output transistor
At what point would the process-control computar be connected to the 'pressure relief control'
clrcuit in the following diagram?
B. point B
c. point e
D. point D
71. Which of these tour motor starters utilizas electronic circuitry/solid state components?
B. across the line
72. What is the tolerance of a resistor color coded: red, red, orange, brown?
73. What are Hall Effect sensors used to detect?
B. RF signals
C. stereo signals
D. altitude changas
74. Load regulation in power supplies is the ability to keep a constant output under conditions of
A curren! dc-e_m_a-nd-:------
B. fine voltage
C. tem perature
lnformation to be processed by a computer mus! be converted to ____ coding.
A frequency modulated
B. amplitude modulated
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