Download Electronic Components and Circuits and more Exams Advanced Education in PDF only on Docsity!
Associate CET Practice Exam Questions And Answers
With Complete Solutions
8.33 meters is the full wavelength in air for what RF frequency? Correct Answer: 36 MHz Decimal 164 would appear as ________ in binary? Correct Answer: 10100100 A resistor has color stripes yellow, violet, violet, silver. It is: Correct Answer: 470 MegOhm +/- 10% what is the total capacitance of three capacitors valued at 100pf, 100pf, and 50pf when connected in a series? Correct Answer: 25 pf what is the ripple frequency of a full wave single phase bridge rectifier operated at 60Hz? Correct Answer: 120Hz When heated or cooled, a ________emits a voltage. Correct Answer: theromcouple Which wire size is physically largest? Correct Answer: # Adding the binary numbers 101011 and 001110 will give you what result? Correct Answer: 111001 A component that reduces in resistance as it is heated: Correct Answer: Is a negative temperature coefficient thermistor An autotransformer: Correct Answer: has a single winding A dual trace oscilloscope differs from a single trace in that only the dual trace scope: Correct Answer: alternates sweeps If an RF signal voltage is reduced by 6 dB, it is then: Correct Answer: half the original size Applying positive voltage to the P end and negative to the N end of a germanium diode: Correct Answer: will forward bias it You would probably prefer a digital VOM over an ordinary analog meter: Correct Answer: for most accuracy You should expect the video amplifier in a radar or TV receiver to have a frequency response of: Correct Answer: 0-6 MHz The radio communication mode that utilizes the basic frequency and one of the side bands: Correct Answer: is called "SSB" When using fiber optics to transfer a signal, the light must: Correct Answer: Enter the "cone of acceptance" The energy stored in a coil is measured in: Correct Answer: Joules The telephone communication term "cellular" refers to: Correct Answer: small geographic areas covered by each base station.
Integrated Circuit failures often exhibit: Correct Answer: open or short conditions Which of these would you normally choose to cause an LED to light? Correct Answer: 3 V DC A capacitor (3/8" x 1/8" ceramic or mica) marked 47K is: Correct Answer: 47pf+/- 10% A digital storage oscilloscope: Correct Answer: uses micro processing and memory to allow close analysis of signals; is specially designed for analyzing digital signals; converts analog input signals to a digital display Carbon microphones are much like variable: Correct Answer: Resistors An antenna that is longer than another: Correct Answer: will have a lower resonant frequency An 8-bit binary code allows ______ logical combinations. Correct Answer: 256 An inductor in an electronic circuit: Correct Answer: resists AC current flow A printer directly connected to a personal computer would use a _______ connection. Correct Answer: USB or parallel Centronics The digital method of representing characters by using combinations of zeros and ones is called: Correct Answer: binary Fm utilizes ______ where AM utilizes signal level variations. Correct Answer: frequency variations What decimal number is represented by the binary number 01101010? Correct Answer: 106 Decimal 50 would appear as _____ in Hex. Correct Answer: 32 Of these choices, the display of a DMM would probably be: Correct Answer: LCD A disadvantage of LCD is: Correct Answer: environmental temperature sensitivity A series DC motor maintains a constant speed with changing loads? Correct Answer: may be damaged by excessive speed Which motor maintains constant speed with changing loads? Correct Answer: Shunt A small power drill or electrics mixer would probably be powered by a/an ______ motor. Correct Answer: series The rotor in an induction motor is not connected to AC or DC power. Correct Answer: True 0 dBm, when referring to audio signals means: Correct Answer: decibels referenced to 1 milliwatt If a class A differential amplifier is using only one of its two possible inputs, what will the output signal shape be? Correct Answer: exactly the same as the one input
The time required to dicharge a capacitor depends on the _____________ across its terminals. Correct Answer: the combination of LRC With a given filter type, pure filtering is easiest with: Correct Answer: high frequencies Using a resistor instead of an inductor in a power supply pi filter: Correct Answer: all of the above A power supply whose output voltage does not change whether the load is light or heavy, would have what percent of regulation? Correct Answer: 0 A power supply which measures 50 volts when under no load and 40 volts under a full load has what percent regulation using the % of regulation formula: (%=(EnL - EfL) / EfL x 100)? Correct Answer: 25 Correctly connecting a properly rated zener diode across a power supply load will: Correct Answer: limit the output DC A triac in a power control circuit: Correct Answer: acts as an on/off switch Which wire gauge has the largest diameter? Correct Answer: 20 What specification should NOT be of concern regarding wire conductors? Correct Answer: Length The normal open circuit voltage for each nickelcadmium cell is approximatley ________. Correct Answer: 1. Lead free type solder for electronics work is made from: Correct Answer: silver and tin Soldering stations used for electronics circuit board work have historically been Correct Answer: 30 watts Solder flux mainly: Correct Answer: removes oxides on metals to be soldered Laminations used for the core of a transformer: Correct Answer: must be insulated from each other. I=1 amp, R=10,000 ohms. What is the value of voltage? Correct Answer: 10,000 volts If R=200 ohms and I=.02 amps. What is the value of P (power). Correct Answer: .08 watts Which frequency will have a higher loss when using coaxial cable transmission line? Correct Answer: 1 GHz A __________ is a reference antenna that all other antennas with gain are compared to. Correct Answer: Dipole A high frequency antenna ________ than a low frequency one. Correct Answer: is shorter Standing waves on a transmission cable: Correct Answer: can be caused by poor termination Sideband frequencies are produced when a radio carrier frequency is: Correct Answer: modulated
Doubling the power in a transmitter output signal is ______ dB gain. Correct Answer: 3 0 dBm V is what levle of received TV signal? Correct Answer: 1000 microvolts A byte is: Correct Answer: 8 bits In a 3 input AND gate: Correct Answer: 3 input must be high for a high output An LCD operates by polarizing the light through filters. The fluid rotates ____________ degrees. Correct Answer: 90 To test an SCR with an ohmmeter: Correct Answer: With + to anode and - to cathode, short gate 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: Correct 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: Correct Answer: high Which is LEAST likey to cause ESD damage to a MOSFET? Correct Answer: flux A logic probe: Correct Answer: indicates high and low voltage conditions In a typical electrical generator, a small AC voltage applied to the field windings is able to control the output level of the generator. Correct Answer: false When working with and testing lead acid batteries: Correct Answer: always wear eye protection, never cause a spark and charge in a ventilated room Audio signals, such as the output from DVD players, satellite receivers and preamplifiers, usually are of what amplitude for input to a TV, modulator or other equipment? Correct Answer: 1 volt peak to peak Which of these signal parameters does a spectrum analyzer show? Correct Answer: Magnitude and frequency Permanent, non-volatile, non-removable data storage in a computer is: Correct Answer: ROM What should be used first to clean a corroded plated soldering iron tip? Correct Answer: Flux, cloth after heating When soldering high voltage connections: Correct Answer: leave the terminal with smooth and rounded covering of solder Class AB operation of an audio amplifier means that current flows through the active device(tube, transistor, FET, IC) for ________ degrees of the input signal wave. Correct Answer: more than 180 but less than 360 A track on a computer removable disk is: Correct Answer: divided into sectors
You are servicing a power supply and have disconnected power. It has several 250 uF capacitors connected in parallel. To avoid shock, these capacitors: Correct Answer: Should be discharged to chassis ground, through a suitable resistor. A schematic used in electronic servicing: Correct Answer: is much like a road map for following signals High voltage should be discharged before servicing a product. After disabling. After disabling AC input power, discharge an HV PS by: Correct Answer: draining through a large value resistor to chassis ground Which of these would be an important electrical consideration in the use of a transformer? Correct Answer: The operating frequency If a 12v product is dissipating 50w, how much load resistance does the device represent? Correct Answer: 2.9 ohms An "audio signal" is often defined as: Correct Answer: frequencies in the 20 Hz to 15,000 Hz range _____________ will cause a generator to produce DC voltage rather than AC. Correct Answer: The communtator You supect the unit has an internal short. To prevent further damage when you apply power, you should: Correct Answer: insert a low resistance high wattage (100 ohm, 10w) resistor in series with the power input A ripple counter: Correct Answer: is two or more logical flip-flops connected sequentially with the input pulses toggling the first When a voltage is applied to a capacitor: Correct Answer: current is maximum at first, then reduces as the capacitor becomes charged An electrolytic capacitor in series between the power transformer and the rectifiers in a power supply: Correct Answer: is part of a voltage doubler circuit Information travels through optic fiber via the flow of: Correct Answer: photons You would most likely prefer an analog VOM over a DMM for: Correct Answer: intermittent functuations Which of these circuits would most likely use a Zener diode? Correct Answer: a power regulator A block in a digital diagram is called a NOR. Which is true? Correct Answer: It is a NOT OR or inverted OR Which of these statements is most true relating to schematic diagrams of electronic devices? Correct Answer: They represent signal paths In personal computer technology, ROM indicates: Correct Answer: memory that may only be read from
A light emitting diode will light when: Correct Answer: it is forward biased A zener diode is rated 6.3 v. This tells you: Correct Answer: it conducts to limit voltage across it to 6. v A triac is frequently used: Correct Answer: to electronically turn equipment on and off A techician must be knowledgeable about "ESD": Correct Answer: because static discharge can destroy many components In a motor, the counter emf voltage induced in the armature ________ the source current. Correct Answer: causes a decrease in One significant difference between a TV antenna and a CB antenna would be: Correct Answer: TV is polarized horizontal while CB is veritcal Switching power supplies: Correct Answer: are sometimes called DC to DC converters Which of these would you likely find in a DC motor speed control circuit? Correct Answer: an op-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 Correct Answer: center tapped secondary transformer The 9 pin DB9 connector serial port on a PC is commonly called the ______ standard. Correct Answer: RS Three capacitors, of 470 pf, 560 pf and .47 pf are in parallel with each other. The total is: Correct Answer: 1030.47 pf Ohm's law provides equations relating to: Correct Answer: volts, amps, and resistance A power source such as a generator to what component in a water supply system? Correct Answer: A pump Which of these is a good indication of the quality of an analog meter? Correct Answer: the ohms per volt rating The vertical axis of an oscilloscope display is also called the: Correct Answer: Y axis If you increase the value of an inductor, the the inductive reactance will: Correct Answer: increase Which would least likely be a high voltage (above 1,000v) capacitor? Correct Answer: Electrolytic The rechargeable cells currently used in many consumer portable products would be: Correct Answer: Lithium ion A solid stat regulator: Correct Answer: varies conduction to maintain a level output voltage
Three series inductors have values of 20 mH, 30 mH and 40 mH respectively. Total inductance is: Correct Answer: 90 mH Phototransistors: Correct Answer: can be sensitive to invisible light To simplify the following of an electrical signal path through circuity, you could: Correct Answer: use block diagram AC power outlet strips with surge suppressors will include at least one: Correct Answer: MOV Connecting 3 capacitors of: .05uF, 20uF, and 40uF in series results in a total capacitance of: Correct Answer: .0498uF You would use the formula (Lt=L1+L2+L3): Correct Answer: to find total inductance in a series circuit The fifth color band on a 5% resistor is yellow. This tells you: Correct Answer: Tolerance VHF or UHF antennas dont use waveguides as feed lines because: Correct Answer: the large dimersions at these wavelengths makes other transmissions lines more practical To trace a logic path, you might use: Correct Answer: A logic pulser Ordinary alpha/numeric information tansmitted by a computer is converted to binary using: Correct Answer: an encoder In electronic devices, what term refers to residual magnetism? Correct Answer: Hysteresis Some variable capacitors are made so that the plates interleave. The capacitance varies as the plates open and close. As they open: Correct Answer: the capacitance decreases In VOM's voltage multiplier resistors are important: Correct Answer: in the voltage scales In a series tuned circuit, to increase the resonant frequency, you need to: Correct Answer: decrease the inductance A MOSFET: Correct Answer: amplifies signal voltage variations Toroid cores are used in transformers for: Correct Answer: concentrating the magnetic flux A PLL, or phase locked loop circuit, contains a VCO, or voltage controlled oscillator. The output of the VCO is a _________. Correct Answer: AC variable frequency signal A variable capacitor depends on: Correct Answer: the plate separation being adjustable While anode and cathode voltages are maintained, the gate level on an SCR drops below the trigger point. What happens? Correct Answer: The SCR stays on The combination of resistance and reactance which restricts the flow of alternating current is called: Correct Answer: Impedance
The output of a thermocouple would most likely be measured in: Correct Answer: millivolts The Z axis on an oscilloscope is: Correct Answer: intensity When soldering transistor or IC chip legs, a _____________ should be used to prevent overheating of the small discrete components. Correct Answer: heat sink clip Which of the below would normally be used for the core of a transformer? Correct Answer: Ferrite The "1" in binary number 100000 carries a weight of: Correct Answer: 32 You would choose an LCD if you needed: Correct Answer: a low current digital display Germanium diodes: Correct Answer: normally drop about .3 V with forawrd current RF signal propagation what is normally considered "line of sight" would be: Correct Answer: UHF
