Download Associate CET Practice Exam Questions and Answers: Electronics Fundamentals and more Exams Advanced Education in PDF only on Docsity!
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8.33 meters is the full wavelength in air for what RF frequency? - ANSWER 36 MHz Decimal 164 would appear as ________ in binary? - ANSWER 10100100 A resistor has color stripes yellow, violet, violet, silver. It is: - ANSWER 470 MegOhm +/-10%
what is the total capacitance of three capacitors valued at 100pf, 100pf, and 50pf whenconnected in a series? - ANSWER 25 pf
what is the ripple frequency of a full wave single phase bridge rectifier operated at60Hz? - ANSWER 120Hz
When heated or cooled, a ________emits a voltage. - ANSWER theromcouple Which wire size is physically largest? - ANSWER # Adding the binary numbers 101011 and 001110 will give you what result? - ANSWER 111001
A component that reduces in resistance as it is heated: - ANSWER Is a negativetemperature coefficient thermistor
An autotransformer: - ANSWER has a single winding
A dual trace oscilloscope differs from a single trace in that only the dual trace scope: -ANSWER alternates sweeps
If an RF signal voltage is reduced by 6 dB, it is then: - ANSWER half the original size Applying positive voltage to the P end and negative to the N end of a germanium diode: -ANSWER will forward bias it
You would probably prefer a digital VOM over an ordinary analog meter: - ANSWER formost accuracy
You should expect the video amplifier in a radar or TV receiver to have a frequencyresponse of: - ANSWER 0-6 MHz
The radio communication mode that utilizes the basic frequency and one of the sidebands: - ANSWER is called "SSB"
When using fiber optics to transfer a signal, the light must: - ANSWER Enter the "cone ofacceptance"
The energy stored in a coil is measured in: - ANSWER Joules The telephone communication term "cellular" refers to: - ANSWER small geographicareas covered by each base station.
Integrated Circuit failures often exhibit: - ANSWER open or short conditions Which of these would you normally choose to cause an LED to light? - ANSWER 3 V DC
A disadvantage of LCD is: - ANSWER environmental temperature sensitivity A series DC motor maintains a constant speed with changing loads? - ANSWER may bedamaged by excessive speed
Which motor maintains constant speed with changing loads? - ANSWER Shunt A small power drill or electrics mixer would probably be powered by a/an ______ motor. -ANSWER series
The rotor in an induction motor is not connected to AC or DC power. - ANSWER True 0 dBm, when referring to audio signals means: - ANSWER decibels referenced to 1milliwatt
If a class A differential amplifier is using only one of its two possible inputs, what will theoutput signal shape be? - ANSWER exactly the same as the one input
voltage is: - ANSWER potential difference between two points _______ is a term describing many op-amp circuits. - ANSWER Inverting The gain of an op-amp is inversely related to band width as input frequency increases. -ANSWER Always
The audio detector circuit in an AM radio most commonly is a: - ANSWER Diode A differential amplifier with two identical in phase signals on the inputs will have anoutput __________. - ANSWER of zero
A free running oscillator is also called a monostable multivibrator. - ANSWER false A fuse which has its fusible wire wrapped around an insulator is: - ANSWER a slo-blotype fuse
The power transformer in a power supply: - ANSWER might step voltages up or down Which of the below would be considered "basic" components of a non switching powersupply? - ANSWER filter, rectifier, transformer
The average of a full sine wave rectified voltage is: - ANSWER .637 x peak The ripple frequency for a half wave rectifier operating from 60 Hz electrical power is: -ANSWER 60 Hz
The effective voltage of a 100V peak to peak sine wave is: - ANSWER 35. A pi filter is an inductor with: - ANSWER a capacitor at each end to common An inductor opposes any change in: - ANSWER current A capacitor opposes any change in: - ANSWER voltage A capacitor will charge to what percent of full charge in one RC time? - ANSWER 63. Moving one plate of a capacitor further away from the other will: - ANSWER decreasecapacitance
Which wire gauge has the largest diameter? - ANSWER 20 What specification should NOT be of concern regarding wire conductors? - ANSWERLength
The normal open circuit voltage for each nickelcadmium cell is approximatley ________. -ANSWER 1.
Lead free type solder for electronics work is made from: - ANSWER silver and tin Soldering stations used for electronics circuit board work have historically been -ANSWER 30 watts
Solder flux mainly: - ANSWER removes oxides on metals to be soldered Laminations used for the core of a transformer: - ANSWER must be insulated from eachother.
I=1 amp, R=10,000 ohms. What is the value of voltage? - ANSWER 10,000 volts If R=200 ohms and I=.02 amps. What is the value of P (power). - ANSWER .08 watts Which frequency will have a higher loss when using coaxial cable transmission line? -ANSWER 1 GHz
A __________ is a reference antenna that all other antennas with gain are compared to. -ANSWER Dipole
A high frequency antenna ________ than a low frequency one. - ANSWER is shorter
Standing waves on a transmission cable: - ANSWER can be caused by poor termination Sideband frequencies are produced when a radio carrier frequency is: - ANSWERmodulated
Doubling the power in a transmitter output signal is ______ dB gain. - ANSWER 3 0 dBm V is what levle of received TV signal? - ANSWER 1000 microvolts A byte is: - ANSWER 8 bits In a 3 input AND gate: - ANSWER 3 input must be high for a high output An LCD operates by polarizing the light through filters. The fluid rotates ____________degrees. - ANSWER 90
To test an SCR with an ohmmeter: - ANSWER With + to anode and - to cathode, shortgate and anode together. Should go from near "open" to near "short."
Using the R x 100 range and testing between the source and drain of an N channel JFET:- ANSWER readings should be equal in both directions
With + voltage to drain or source and a - voltage to the gate on an N channel JFET,internal resistance of the JEFT will be: - ANSWER high
Which is LEAST likey to cause ESD damage to a MOSFET? - ANSWER flux A logic probe: - ANSWER indicates high and low voltage conditions
Which video system has the highest resolution? - ANSWER XVGA You would want to use a dual trace oscilloscope to measure: - ANSWER signaldifferences between two points
Common Intermediate Frequencies (IF's) for AM and FM commercial broadcastreceivers are: - ANSWER 455 kHz and 10.7 MHz
Analog radio receiver signal compression: - ANSWER reduces the high frequencyreceived signal amplitude
Coaxial cable line losses at RF frequencies are due to: - ANSWER wire resistance,capacitive and inductive reactance
You are troubleshooting audio reproduction equipment and measure the signal to beinput into the audio amplifier. What approximate RMS level would you except that signal to be? - ANSWER 1,000 millivolts The noise level in a radio receiver is generated mostly in the: - ANSWER RF section The fast charging rate for a NiCad or Ni-MH battery should not exceed _______% of itsAHr, or ampere hour rating? - ANSWER 10
Which one of the following in a PC would be part of disk operations? - ANSWER SATA orIDE controller
An LED: - ANSWER can be used as a fiber optic signal source A dual trace oscilloscope may have: - ANSWER a Z input for intensity modulation
The gain of an-amp connected as an inverting amplifier is determined by the external_______. - ANSWER feedback and input resistors
Diodes are made from one type of material. - ANSWER false Which propagation condition would be significant for UHF signal to be received at adistance of 500 miles? - ANSWER Tropospheric ducting
A three input NAND has two low inputs and one high input. The output is: - ANSWERHigh
Which of these would be considered a component of "basic" power supply? - ANSWERDiode rectifer
A "video signal" is defined as: - ANSWER Baseband including visual information. You are servicing a power supply and have disconnected power. It has several 250 uFcapacitors connected in parallel. To avoid shock, these capacitors: - ANSWER Should be discharged to chassis ground, through a suitable resistor. A schematic used in electronic servicing: - ANSWER is much like a road map forfollowing signals
High voltage should be discharged before servicing a product. After disabling. Afterdisabling AC input power, discharge an HV PS by: - ANSWER draining through a large value resistor to chassis ground Which of these would be an important electrical consideration in the use of atransformer? - ANSWER The operating frequency
inverted OR Which of these statements is most true relating to schematic diagrams of electronicdevices? - ANSWER They represent signal paths
In personal computer technology, ROM indicates: - ANSWER memory that may only beread from
A light emitting diode will light when: - ANSWER it is forward biased A zener diode is rated 6.3 v. This tells you: - ANSWER it conducts to limit voltage acrossit to 6.3 v
A triac is frequently used: - ANSWER to electronically turn equipment on and off A techician must be knowledgeable about "ESD": - ANSWER because static dischargecan destroy many components
In a motor, the counter emf voltage induced in the armature ________ the source current.- ANSWER causes a decrease in
One significant difference between a TV antenna and a CB antenna would be: - ANSWERTV is polarized horizontal while CB is veritcal
Switching power supplies: - ANSWER are sometimes called DC to DC converters Which of these would you likely find in a DC motor speed control circuit? - ANSWER anop-amp
A transformer on a schematic has two leads connected to the primary and three to the
secondary, one on each end and one in the middle. This is a - ANSWER center tappedsecondary transformer
The 9 pin DB9 connector serial port on a PC is commonly called the ______ standard. -ANSWER RS
Three capacitors, of 470 pf, 560 pf and .47 pf are in parallel with each other. The total is:- ANSWER 1030.47 pf
Ohm's law provides equations relating to: - ANSWER volts, amps, and resistance A power source such as a generator to what component in a water supply system? -ANSWER A pump
Which of these is a good indication of the quality of an analog meter? - ANSWER theohms per volt rating
The vertical axis of an oscilloscope display is also called the: - ANSWER Y axis If you increase the value of an inductor, the the inductive reactance will: - ANSWERincrease
Which would least likely be a high voltage (above 1,000v) capacitor? - ANSWERElectrolytic
The rechargeable cells currently used in many consumer portable products would be: -ANSWER Lithium ion
A solid stat regulator: - ANSWER varies conduction to maintain a level output voltage
A thermistor: - ANSWER changes resistance with temperature When a transformer is designed, what most determines the output voltage from thesecondary? - ANSWER the ratio of primary to secondary turns
Adding armature winding in parallel to a generator's existing windings: - ANSWERimproves its voltage stability
A 10W signal is received at 5W. This is a ____________dB loss. - ANSWER 3 Its is desired to raise the power to a speaker from 15W to 30W. This is a: - ANSWER 3 dBincrease
Which of these IC or semiconductor devices normally requires the most careful handlingto avoid damage by static electricity? - ANSWER CMOS
Which of these components most closely compares to the output of a solar cell? -ANSWER A NiCad battery
Three series inductors have values of 20 mH, 30 mH and 40 mH respectively. Totalinductance is: - ANSWER 90 mH
Phototransistors: - ANSWER can be sensitive to invisible light To simplify the following of an electrical signal path through circuity, you could: -ANSWER use block diagram
AC power outlet strips with surge suppressors will include at least one: - ANSWER MOV Connecting 3 capacitors of: .05uF, 20uF, and 40uF in series results in a total
capacitance of: - ANSWER .0498uF You would use the formula (Lt=L1+L2+L3): - ANSWER to find total inductance in a seriescircuit
The fifth color band on a 5% resistor is yellow. This tells you: - ANSWER Tolerance VHF or UHF antennas dont use waveguides as feed lines because: - ANSWER the largedimersions at these wavelengths makes other transmissions lines more practical
To trace a logic path, you might use: - ANSWER A logic pulser Ordinary alpha/numeric information tansmitted by a computer is converted to binaryusing: - ANSWER an encoder
In electronic devices, what term refers to residual magnetism? - ANSWER Hysteresis Some variable capacitors are made so that the plates interleave. The capacitancevaries as the plates open and close. As they open: - ANSWER the capacitance decreases In VOM's voltage multiplier resistors are important: - ANSWER in the voltage scales In a series tuned circuit, to increase the resonant frequency, you need to: - ANSWERdecrease the inductance
A MOSFET: - ANSWER amplifies signal voltage variations Toroid cores are used in transformers for: - ANSWER concentrating the magnetic flux
UHF
