CET Quizlet
A power supply is found to have several 250 uF capacitors connected in parallel. To avoid shock from retained charge after disconnecting the power, the capacitor should be:
discharge to chassis ground
An inductor with the same length of wire but whose turns are spread further apart will have....
less inductance.
A DC voltmeter multiplier resistor______
limits the mieter movement current to its full scale value
The primary difference between a NPN and a PNP transistor is....
DC voltages are reversed.
In an AC circuit as the applied voltage frequency increases the capacitive reactance in the circuit will: a. decrease b. increase c. stay the same d. either increase or decrease
Decrease. Xc= 1/(2piFC)
The Journeyman level: a. denotes competency in one specialized area b. requires 75% passing c. requires 2 years of work or school d. all of the above
Denotes competency in one specialized area
Who knows the most about a piece of equipment?
The operator
Series wound AC motors have strong torque from a dead stop. This makes them ideally suited for use in small appliances. True or False.
True
The orientation of the transmitter antenna and the receiver antenna must match for ideal reception. True or false.
True
Maximum power transfer occurs when the load impedance is equal to the source impedance. True or False.
True.
Maximum power transfer to the load occurs when the load impedance matches that of the transmission line. True or false.
Ture
What does a low pass T circuit look like?
Two inductors make up the top part of the "T" and a capacitor makes up the trunk of the "T"
A circle is obtained on the scope when:
Two sine waves that are 90 degrees out of phase fed to the vertical and horizontal inputs
Name one safety precaution taken before replacing a transistor.
Short emitter to base to remove discharge voltage.
B+ or supply voltages in electronics products are considered to be: a. +5 to +12 V DC b. 0 to 30 V DC c. +12 to 300 V DC d. the anode or plate voltage supply
+12 to 300V DC
Analog telephone lines have what DC voltage level across the tip and ring when off-hook? a. 110 VDC b. 6 VDC c. -48 d. depends on length of line
-48 V DC
On hook DC voltage on a telephone local loop is____ a. +24 volts b. -8 Volts c. -48 volts d. +12 volts
-48 volts
Which is the equivalent to 100 microamps? a. .1 milliamps b. 1 milliamps c. 10 milliamps d. 10 nano amps
.1 milliamps
A certain transformer has 250 turns in the primary winding and 1250 turns in the secondary winding turns ratio is_________
.2
To properly bias a NPN silicon signal amplifier transistor, which voltages appear correct for a signal amplifier (SI?)
.7 difference between the base and emitter and a negative bias
When the turns ratio of a transfomer is 10 and the primary AC voltage is 8V, the secondary voltage is________
.8 V
The number 25 in octal is _________in binary.
010101
Which frequency is most commonly used for audio troubleshooting?
1 KHz
Which frequency is most commonly used for audio troubleshooting? a. 1000KHz b. .1KHz c. 1 Hz d. 1 KHz
1 KHz
The +5V level of a TTL digital signal is called logical.....
1 or high.
1 kilohm is the same as (how many ohms?).....
1 thousand ohms
How many RC time constants does it take to charge a capacitor to 63% of the applied voltage?
1 time constant
How do you calculate the gain of a non-inverting operation amplifier?
1+ (Rf/Ri)
One microfarad is equivalent to ______picofarads
1,000,000
What are the three types of coupling?
1. direct 2. Capacitor 3. transformer
A NiMH battery cell, when charged, has a terminal voltage of....
1.2 volts
The max bit rate available on a T-1 transmission system is _________ a. 56 kbps b. 64 kbps c. 1.544 Mbps d. 2.4 Gbps
1.544 Mbps
What is the binary number for decimal number 9?
1001
165 decimal converted to binary would be.....
10100101
the number 12 in decimal is ______ in binary
1100
A 12 vdc power supply has a 15 ohm internal resistance. What load resistance can be connected to transfer max power?
15 ohms
When did the first CET certification program begin?
1965
When did ETA initiate certification maintenance?
1996
Given the following information about a common-emitter amplifier, a .01Vp-p input signal causes transistor's base current to vary from 70uA to 50uA. This causes the collector current to vary from 3.5mA to 2.5mA through our 2.2kohm load. Determine the dynamic current gain.
2.5mA/50uA= 50
A simple DC voltmeter with a 200ua meter movement needs to have how much internal resistance on it 50 volt range?
250kohms
A resistor has color bands orange, red, brown. It is what value?
320 ohms
8.33 meters is the full wavelength in air for what RF frequency?
36MHz
A circuit has one 500 ohm resistor in series with three 500 ohms resistors in parallel with each other. What is the total resistance?
500 + 1/( (1/500) + (1/500)+ (1/500)) = 666
Leakage current in an electronic product between either of the AC power cord conductors and the chassis or any exposed metal parts should not exceed.... a. 5 microamps b. 500 microamps c. 5 milliamps d. 50 milliamps
500 microamps
The most common solder used by electronics technicians consists of what materials and of what percent?
60% tin and 40% lead
Hexidecimal 3E is equivalent to a decimal number of: a. 62 b. 46 c. 37 d. 48
62
The bandwidth of a standard definition analog TV signal is:
6MHz
The DTMF tones for the number 5 on a telephone keypad is_______
770+1336 Hz
The input of the op amp below is a .5V sine wave (centered about +2). What will the output be?
A 1 V sine wave centered about -4V
Which portion of the microprocessor would perform the addition of two numbers? a. ALU b. Bus Control c. Instruction decoder d. register
ALU ( arithmetic logic unit)
The three basic logic gates are______.
AND, OR, NOT
What does a pi filter look like?
An inductor with a cap on either side. the caps are grounded.
The formula for calculating productivity is:
B/T=P(100) =P%
Which would be the likely cause of hum in an amplifier but only present when the CD position is selected?
Bad shielded cable from the CD playe4r
Which would be the likely cause of hum in an amplifier but only present when the DC position is selected?
Bad shielded cable from the CD player
Flexible coaxial transmission lines are ideal for what frequencies? a. MHZ only b. KHz only c. Above GHz d. Below GHz
Below GHz
A class AB amplifer will allow output current to flow for approximately____ of the input signal. a. 100 degrees b. 180 degrees c. 280 degrees d. 360 degrees
Between 180 and 360 degrees so... c. 280 degrees
What is the saying to remember resistor values and what value corresponds with each letter?
Black-0 Boys-1 Rape -2 Our -3 Young-4 Girls-5 But -6 Violet-7 Gives-8 Willingly-9
Why is a coupling capacitor used when troubleshooting with signal injection?
Block DC Level present
Why is a coupling capacitor used when troubleshooting with signal injection?
Block DC level present
Which component of a microcomputer connects all of the sub systems together?
Bus
The capacitance of a capacitor with 10uC of electric charge and 100V across its plates is___________
C=Q/V C= .1uF
The form of signaling used on telephone systems today is______ a. ACS b. ISDN c. POP d. CCS
CCS
ESD and static discharge is most destructive to... a. CMOS semiconductors b. TTL semiconductors c. Germanium PN junctions d. Silicon PN junctions
CMOS semiconductors
What is the effect on a varactor (varicap) when the reverse bias voltage is increased?
Capacitance decreases and the tuned frequency increases.
What happens to the value of a capacitor if the spacing between plates decreases?
Capacitance increases.
How is the capacitance of two capacitors in series calculated?
Capacitors in series are calculated like resistors in parallel.
Diodes are marked with a band at the______end.
Cathode
Which of the following amplifier configurations would you likely find being used in a linear push-pull arrangement?
Class B or AB.
What element of a DC generator distinguishes it from an AC generator?
Commutator
What is wrong with this circuit below?
Diode grounds are shorting.
An associate CET cannot attempt one of the specialty examinations. True or false.
False
Cables of different impedances may be combined for short runs.
False
To qualify for MASTER CET, the examinee must attain a score of 85% on each separate exam. True or false.
False
All ETA Certification categories require the passage of the Associate CET examination. True or false.
False.
The associate CET exam may be taken after the Journeyman exam. True or false.
False.
The atomic number of an element is the same as the elements atomic weight. True or false.
False.
The solder traditionally used is a metal alloy consisting of zinc and copper. True or false.
False.
When measuring power to a speaker, a doubling of the power represents a 6dB increase. True or false.
False. (3dB)
In testing germanium diodes, a forward to reverse ratio of 10-1 is indicative of a good diode. True or false.
False. You want a ratio greater than 10-1.
What is the oldest piece of troubleshooting equipment a technician has?
Five senses
List of powers of tens/prefixes (in descending order from largest to smallest)
Giga (10 to the power of 9) Mega (10 to the power of 6) Kilo (10 to the power of 3) base unit (10^0) milli (10^-3) micro (10^-6) nano (10^-9) pico (10^-12)
How is a fuse installed in a circuit to insure proper operation?
In series with the load.
The basic formula for wavelength is: L=wavelength, v=velocity, f=frequency
L=v/f
Waveguides are not utilized at HF or VHF frequencies because: a. characteristic impedance is too high b. resistance to high frequencies is too high c. large waveguide dimensions required at lower frequencies are not practical. d. grounding problems.
Large waveguide dimensions are required at lower frequencies are not practical.
A conducting loop in motion through magnetic lines of flux has a current induced in it. The physical law that explains this is what?
Len's Law
Space waves are ideal for what frequency of communications?
Line of sight UHF
What happens to current flow in a capacitor when the DC voltage across it has increased to the applied voltage?
Little current flows.
Which one of the following integrated circuit or semiconductor devices normally requires the most careful handling to avoid damage by static electricity?
MOS
Rules describing the fire or toxicity retardant types of cabling which may be installed in buildings is contained in... a. NEC Article 770 b. UL 568B c. TIA/EIA standard 578 d. NEMA code 1316
NEC article 770
_______cell are prone to battery memory.
NiCad
What type of motor will speed dangerously out of control if not physically loaded?
Series wound DC motor
What type of control has the controlled element in either the full open or full closed position?
ON/OFF
The Boolean expression Y=A+B represents..... a. AND b. NAND c. OR d. NOR
OR
Which type of circuit has the same voltage drop across each component.
Parallel
Which of the following circuits can be used to recover audio from an IF in a FM receiver?
Phase locked loop
A stereo amplifier has severe hum whether CD, AUX, FM or AM RADIO are selected. What is the most likely cause?
Power cord polarity is wrong.
What radio receiver section determines the radio's inherent noise level? a. RF b. Mixer c. IF d. Detector
RF
This section of the DC power supply changes AC into pulsating DC.
Rectifier
In the normal layout of a DC power supply the order of the sections would be:
Rectifier Filter Regulator
Which of these color code patterns is found on a 270 ohm, 5% resistor?
Red, violet, brown, gold
Which of these is within tolerance for a resistor color coded red, black, red gold.
Red-2 Black-0 Red (multiplier)- 2 zeros 2000 with 5% tolerance
Which of the below will cause distortion at high audio levels in an amplifier system?
Rubbing speaker coil
An AC induction motor requires what to operate?
Slip
Which of the following words is in the acronym TEST?
Technical Education
If the gate voltage level that turns an active SCR on, drop below the trigger point, while anode and cathode voltages are maintained, what will occur?
The SCR stay on. (latch)
In a transistor, which section is made very thin compared with the other two?
The base
A length of coaxial cable, used for computers, radio or television signals, is open at both ends. With an ohm meter, the resistance measured from the center conductor to the shield is 50 ohms. What does this indicate?
The cable is partially shorted.
What will happen to the current through a resistor if the resistor value increases?
The current decreases.
Master CET status is lifetime and does not require certification maintenance. True or false.
True
Which part of a transistor carries the most current?
The emitter
In a series AC circuit with a resistor, inductor and capacitor, each with the same resistance or reactance, a voltmeter measuring each individual voltage drop would find:
The voltage drops equal to each other
Which of the following is not a characteristic of a series circuit? a. circuit components have a division of the supply voltage. b. all components share one current c. energy is shared by reactive devices d. there is a different level of current in the reactive components than in the resistive components.
There is a different level of current in the reactive components than in the resistive components.
A worker may become certified by ETA as a CST (computer service technician) without also becoming certified as a CET (certified electronics technician.) True or false.
True
Certification maintenance requires payment of a fee and retesting or proving at least 40 hours of upgrade retraining within a four year period.
True
In a generator a DC voltage applied to the field windings controls the output level. True or False.
True
When taking voltage from the output of the transformer secondary is it in Vrms or Vp?
Vpeak
A .1 uF capacitor in a circuit with a frequency of 100kHz applied has a reactance of:
Xc= 1/(2pi*100kHz*.1uF) = 15.92 ohmns
A 50KHz AC voltage is applied to a 10mH inductor its reactance at this frequency is:
Xl=2pi*50kHz*10mH =3140 ohms
Is the value of a 500 picofarad capacitor and a .5 nanofarad capacitor identical?
Yes
Shock hazards exist ecspecially in a power supply which has......
a full wave bridge rectifier connected directly to the AC power source
A ripple frequency of twice the AC frequency is normally associated with......
a full wave rectifier.
The switching power supply used in a PC takes the input from the AC line and changes it to......
a higher frequency.
A green light usually indicates______ a. a logic high b. a logic low c. a TTL logic level d. a CMOS device
a logic low
An LCD (liquid crystal display) is: a. an inductive coupling device b. a lithium/cadmium DC source c. a low current digital display d. a charge coupled device
a low current digital display
Changing the filter capacitor from 10 mF to 50 mF would result in:
a lower ripple voltage.
The safest accessory item for a tie is_____
a tie bar
The ampere expresses__________. a. volts/sec increase b. a unit of charge movement per second past a given point. c. coulombs/charge d. an increase in resistance
a unit of charge movement per second past a given point
Record keeping is needed for which activities? a. customer service b. warranty service validation c. business planning d. all of the above
all of the above
An AC generator is also known as a_______
alternator
The formula: Change in Voltp/ Change in Vg with Ip constant is used to determine the....
amplification factor of the vacuum tube.
Retrace blanking in an oscilloscope is_______ a. not used b. applied to the z axis c. used to blank the vertical retrace d. applied to the x axis
applied to the z axis
Ingested solder fumes or particles... a. are not harmful to the human body b. are toxic c. from lead-tin solder aren't harmful d. from tin alloys are most harmful
are toxic
Which factor determines the value of a capacitor?
area of the plates
Logic pulse can be used as a: a. logic probe b. digital tracer c. digital signal generator d. filter
digital signal generator
Which of the following terms is associated with a commercial receiver being able to reject image frequencies? a. Sensitivity b. selectivity c. discrimination d. bandwidth
bandwidth
Forms should be filled in using________
black ink ballpoint pen
The total resistance of a parallel circuit contain equal branch resistances is found by the following________
by dividing the resistance value of a branch by the number of branches.
A personal field notebook_______
can help the technician keep track of special requests and reference materials
An electronic power supply may be designed to_________
change DC to DC change AC to AC change the frequency change AC to DC
Residual voltage is associated with_______ a. northern lights b. corona arcing from electrical generators c. charge retained by inductors d. charged retained by capacitors.
charge retained by capacitors
Keeping a record for profitability purposes ensures that________ a. the appropriate taxes may be remitted b. client invoices are properly processed c. preventive maintenance schedules are correct d. none of the above
client invoices are processed.
Which transistor circuit normally produces the largest voltage gain?
common base
Choose three of the following amplifier configurations that yield the highest power gains. a. common-grid b. common-cathode c. common-plate d. common-source e. common-gate f. common-drain g. common emitter h. common-base i. common-collector
common-cathode common-source common-emitter
What will cause a generator to produce DC voltage rather than AC voltage?
commutator
The velocity factor in a transmission line is: a. equal to the termination impedance b. determined by the line length c. increased by the distributed capacitance and inductance of the line d. compared to free space velocity
compared to free space velocity
What is the most important service you provide? a. Technical expertise b. equipment repair c. intelligence d. customer service
customer service
What type of control handles the rate of change of the error?
derivative
A negative temperature coefficient thermistor will:
decrease in resistance with increased temp.
A variable capacitor's plates can open or close. As the plates open, capacitance.....
decreases
If the frequency of the broadband input signal to an Op-Amp0 increaes, then the output signal level__________
decreases
A x10 probe has what effect on circuit testing? a. increases circuit loading b. increases the signal level by 10 times c. lowers the effective input impedance d. decreases circuit loading that a direct probe presents
decreases the circuit loading that a direct probe presents
Three phase power is obtained from an AC generator by wiring the armature windings in a_______ or ________ configuration.
delta and wye
A CLEC is a. a cable TV company b. the incumbent telephone company. c. a wireless provider d. either a or c
either a cable tv company or a wireless provider
Electromagnetic field polarization is determined by orientation of what part of the electromagnetic wave? a. magnetic lines of force b. electric lines of force
electric lines of force
The ripple voltage is higher than the specification but the frequency is correct. The section causing this problem is the_____
filter
Total impedance of a circuit is found by: a. adding up all the series resistance and reactance values. b. subtracting all the inductive reactances from all the capacitive reactances and adding the resistors' values. c. finding the net reactance and the net resistance, square each seperately, add them together and then find the square root of the sum. d. divide the applied voltage by the addition of all the circuit components individual currents.
find the net reactance and the net resistance, square each separately add them together and then find the square root of the sum.
Another name for an astable multivibrator is_______ a. latch b. one shot c. free running d. mono
free running
When working at heights above 6 feet, a.____________ is required by OSHA rules. a. linemen's belt b. lineman's belt attached to a lanyard c. full body harness attached to a lanyard which prevents more than a 6' drop d. good insurance policy
full body harness attached to a lanyard which prevents more a 6' drop
Quarter-wave antennas must be ______ at one end for resonance at the desired frequency. a. shielded b. ungrounded c. in free space d. grounded
grounded
common emitter
has both current and voltage gain
common collector (emitter follower)
has current gain by no voltage gain
A MOSFET
has high input impedance.
Germaninum diodes....
have .3V forward voltage drop
A short allows for an increase in current and...... a. voltage b. resistance c. heat d. trouble
heat
The proper process for soldering two objects together is....
heat both surfaces at the same time-apply solder.
The term for the combination of resistance and reactance that restricts the flow of alternating current is.....
impedance
Standing waves occur on a transmission line when there is a_______ between the transmission line and the load. a. impedance match b. impedance mismatch c. resistance match d. capacitive reactance match
impedance mismatch
A resistor___________ a. stores an electric charge b. is measured in coulombs c. in a circuit causes a voltage drop from one end of the resistor to the other end. d. is dependent on lines of force
in a circuit causes a voltage drop from one end of the resistor to the other.
An increase in voltage with resistance held constant causes current to________ a. decrease b. increase twice to the value of voltage c. increase d. none of the above
increase
Decreasing the inductance in a series tuned circuit will cause the resonant frequency to....
increase
In an AC circuit, as the applied voltage frequency changes upward, the inductive reactance in the circuit will: a. decrease b. increase c. stay the same d. either increase or decrease
increase. As frequency goes up, inductance goes up. Xl= 2piFL
A service repair ticket provides: a. information about the who, what, when, where, why and how regarding the service call b. information to the client regarding warranty and payment terms c. information on out of inventory parts d. information on productivity
information about the who, what, when, where, why and how regarding the service call.
What type of control handles long term errors? a. ON/OFF b. proportional c. integral d. derivative
integral
What is the name of the diagram that shows all the general cable connections of a piece of equipment?
interconnect diagram
Which type of program runs the slowest? a. assembly language b. machine language c. interpreted language d. compiled language
interpreted language
Ferrite________ a. is a capacitor dielectric b. is a common inductor core material c. is the most common resistor d. causes faulty saturation of inductors
is a common inductor core material.
Calculating the total capacitance of several capacitors connected in parallel_______ a. is not necessary as they are not used this way b. causes a need to consider inductance factors c. is done by adding each of the capacitance values d. is the same as the power factor
is done by adding each of the capacitance values
An AC voltmeter will measure a non sine wave signal accurately only if_______ a. an extender resistor is used b. it is an average reading meter c. it is a true RMS meter d. the signal crest factor is very high
it is a true RMS meter
To accurately measure a resistance across a transistor's emitter base junction use a. higher ohmmeter range than you normally would b. lower ohmmeter range than you normally would c. high ohms function d. low ohms function
low ohms function
Which of the following languages can run directly on the microprocessor? a. Assembly language b. interpreted language c. machine language d. compiled language
machine language
Antenna resonance is the characteristic permits________radiation of the transmitted signal.
maximum
In a parallel circuit when the inductive reactances equal the capacitor reactances the circuit has_______impedance.
maximum
In telecommunications work_______is replacing pair cabling. a. microwave b. wireless c. fiber optics d. both b and c
microwave and fiber optics
A thermocouple has an output in the range of...
millivolts
In a series circuit when the inductive reactances equal the capacitor reactances, the circuit has_______impedance
minimum
What is the process of imposing intelligence on a carrier wave? a. extrapolation b. modulation c. transmission d. oscillation
modulation
A logic 1, for a TTL device is________ a. more than 1 volt b. more than 1.5 volts c. more than 2 volts d. more than 3.5 volts
more than 2 volts
A logic 1, for a CMOS device connected to a 5V supply is________. a. more than 1 volt b. more than 1.5 volts c. more than 2 volts d. more than 3.5 volts
more than 3.5 volts
An average reading AC voltmeter_________ a. displays the average AC voltage value b. converts to a peak reading before displaying the voltage c. multiplies the average value by 1.111 before displaying the voltage d. multiplies the average value by .636 before displaying the voltage
multiplies the average value by 1.111 before displaying the voltage
Second degree skin burns should... a. not be treated with ice and bandage pack b. be covered with thick bandages c. be treated with cold water or ice d. be treated by draining blisters
not be treated with ice and bandage pack
Shaded components on electronics schematics means... a. only factory service personnel may change the part b. only exact replacement parts may be used. c. the shading makes for better readability d. high voltage is present on these parts
only exact replacement parts may be used.
An inductor in an electrical circuit.....
opposes the flow of AC current.
Oscillators use quartz crystals that generate output by the : a. phase shift effect b. piezoelectric effect c. doppler effect a. avalanche (zener) effect
piezoelectric effect
When connecting an analog voltmeter into a DC circuit, what should be observed? a. RMS rating of meter b. loading of meter c. polarity d. peak to peak voltage of circuit
polarity
A type of transformer which has a 1:1 turns ratio________
provides a floating secondary reference point
A voltmeter that converts AC to DC to rectify the voltage would be least accurate measuring what types of alternating voltages? a. pulses b. sine waves c. peak voltages d. UHF signals
pulses
What does RAM mean?
random access memory
The ripple frequency of the output of a full wave rectifier power supply measures the same as the AC input. The section causing this problem is the_________.
rectifier
Integrated circuit packages
reduced space requirements
Use of a x10 scope probe instead of a direct probe does what?
reduces circuit loading increases the effective input impedance decreases the signal to the scope
The zener diode is the most important component in this section.
regulator
This section of the DC power supply would provide steady DC voltage to a system.
regulator
The voltage rating of a capacitor__________ a. must be factored into the reactance formula b. relates to the maximum voltage that should be applied to it c. indicates the max current the capacitor can allow d. is the same as the power factor
relates to the max voltage that should be applied to it.
Carbon microphones are much like variable: a. capacitors b. resistors c. thermistors d. inductors
resistors
Total capacitance of capacitors connected in parallel is calculated like....
resistors in series
Movement of any component of the solder connection before the solder has hardened:
results in poor electrical connection
Zener and varactor diodes are usually_______biased.
reversed.
An inductor shorted turn can be detected reliably using a __________ a. leakage test b. ringer test c. AC impedance bridge d. all of the above
ringer test
Diagnosing component failures requires the use of a
schematic design
If you have never received formal training and practiced CPR on a person or dummy, in the event of finding a fellow worker not breathing you... a. should use what knowledge you do have of the procedure and attempt it. b. should not attempt it but call for help c. should attempt it after calling for help d. should, if handy, read the instructions and attempt it in order to save the life.
should not attempt it but call for help
Which device is capable of causing magnetic or inductive damage to electronics devices?
soldering gun
Tinning of_____makes the best connections.
soldering iron tip stranded wire component leads
Total power in a series circuit is determined by the.....
source voltage multiplied by the current
Surface mount components do not require mechanical bonding because:
the components are so small the solder connection holds them adequately.
AC motor speed depends on____________
the frequency of voltage applied to it
The term Henry refers to_______ a. the inductive property of a coil b. the inventor of inductors c. reactance of LR circuits. d. resonant frequency of tank circuits
the inductive property of a coil
A new computer gave a POST disk drive error the first time it was powered up. A new disk drive was installed and the same error was displayed. The hard disk cables were replaced and still the problem perished. The motherboard was replaced and the system finally operated properly. After a day of operation the error returned. the most likely cause of the trouble_________is
the power supply
A repair is only as good as.... a. the test equipment b. the equipment brand c. the part replacement d. the soldering
the soldering
Resonance is when_______ a. all resistances in an AC circuit are equal to each other b. all reactances are equal on each reactive component c. the total of the inductive reactances in the circuit equal the total of all capacitive reactances. d. no current is flowing through an AC circuit when a voltage is applied.
the total of the inductive reactances in the circuit equal the total of all capactive reactances.
To remove solder from a joint using copper braid:
touch the joint with the brad--heat it and let the solder wick up the braid.
this section of the DC power supply would step up or step down the voltage.
transformer
Overheating the component lead will likely damage_______first. a. transistors b. diodes c. capacitors d. transformers e. transistors and diodes
transistors and diodes
A trunk connects__________ a. two telephone lines b. two central offices c. two conductors d. two area codes
two central offices.
A dual trace scope has: a. two focus controls b. two sets of position controls c. two vertical inputs d. both b and c
two sets of position controls and two vertical inputs
A circle is obtained on the scope when.....
two sine waves that are 90 degrees out of phase are fed to the vertical and horizontal inputs.
A technician should______ a. understand the record keeping process b. let administration staff do all record keeping c. make multiple copies of all records they file d. allow the client to fill in their own forms
understand the record keeping process
The NAND gate is sometimes called______
universal gate
The best way to remove an IC chip which is soldered into a PC board is to:
use a desoldering adapter tip which heats all pins simultaneously
Before returning the equipment to the customer it is important that you_________
verify operation
Before beginning to troubleshoot, what should you do? a. verify the failure b. call your friend c. disassemble the equipment d. divide and conquer
verify the failure
The Y axis of an oscilloscope is: a.brightness b. intensity c. focus d. vertical
vertical
common base
voltage gain but not current gain
The formula u*Rl/ (Rl+rd) is used to calculate.....
voltage gain of a JFET amplifier
The 30-30-30 rule refers to:
wages, overhead expenses and productivity
