CET Study Guide Exam 294 Questions with Verified Answers,100% CORRECT, Exams of Physics

Download CET Study Guide Exam 294 Questions with Verified Answers,100% CORRECT and more Exams Physics in PDF only on Docsity! CET Study Guide Exam 294 Questions with Verified Answers B+, or supply voltages in electronics products, is considered to be: A. +5 to +12 VDC B. 0 to 30 V DC C. +12 to 300 V DC D. The anode or plate voltage supply - CORRECT ANSWER A: +5 to +12 VDC 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 micoamps B. 500 microamps C. 5 milliamps D. 50 milliamps - CORRECT ANSWER D: 50 milliamps Shaded components on the electronics schematics mean: 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 - CORRECT ANSWER B: Only exact replacement parts may be used 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 - CORRECT ANSWER B: are toxic 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 - CORRECT ANSWER A: not be treated with ice and bandage pack rules describing the fire or toxicity retardant types of cabling which may be installed in buildings is contained in: A. NEC Article 70 B. UL 568B C. TIA/EIA standard 578 D. NEMA code 1316 - CORRECT ANSWER A: NEC Article 70 ESD and static discharge is most destructive to _______. A. CMOS semiconductors B. TTL semiconductors C. Germanium PN junctions D. Silicon PN junctions - CORRECT ANSWER A: CMOS semiconductors If you have never received formal training and practiced CPR on a person or dummy, in the event of finding a fellow worker not breaking, you____. A. should use what knowledge your 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 - CORRECT ANSWER B: should not attempt it, but call for help When working at heights above 6 feet, a ____ is required by OSHA rules. A. lineman's belt B. lineman's belt attached to a lanyard C. full body harness attached to a lanyard which prevents more that a 6' drop D. good insurance policy - CORRECT ANSWER C: full body harness attached to a lanyard which prevents more than a 6' drop residual voltage is associated with ______. Maximum power transfer occurs when the load impedance is equal to the source impedance. True or False. - CORRECT ANSWER True *Picture Adobe Chapter 4 (pic 2)* What is the current through the resistor in the schematic below? A. .2 amps B. 2 amps C. 5 amps D. 50 amps - CORRECT ANSWER B: 2 amps *Picture Adobe Chapter 4 (pic 2)* In the circuit above, what is the power dissipated in the resistor? A. 6 watts B. 12 watts C. 2 watts D. 24 watts - CORRECT ANSWER D: 24 watts What will happen to the current through a resistor if the resistor value increases A. current increases B. current remains unchanged C. current decreases D. current and the voltage across the resistor increases - CORRECT ANSWER C: current decreases Which type of circuit has the same voltage drop across each component? A. parallel B. series-parallel C. series D. combination - CORRECT ANSWER A: parallel Total power in a series circuit is determined by the: A. source voltage times the current B. total voltage applied to the circuit C. current flowing through the switch D. average wattage rating of each resistor - CORRECT ANSWER A: source voltage times the current Which is the equivalent to 100 microamps? A. .1 milliamps B. 1 milliamp C. 10 milliamps D. 10 nanoamps - CORRECT ANSWER A: .1 milliamps *Picture Adobe Chapter 4 (pic 3)* If the current drain from the battery is 4mA, what resistance is the rheostat in the drawing below? A. 1k ohm B. 2.5k ohm C. 5k ohm D. 10k ohm - CORRECT ANSWER B: 5k ohm *Picture Adobe Chapter 4 (pic 4)* In the circuit below how much current is flowing in R2? A. 1 amp B. 2 amps C. 10 amps D. 100 amps - CORRECT ANSWER A: 1 amp 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 - CORRECT ANSWER C: in a circuit causes a voltage drop from one end of the resistor to the other end 1k ohm is the same as ______. A. 1000 ohms B. .001 ohm (one thousandth) C. .01 ohm D. 10,000 ohm - CORRECT ANSWER A: 1000 ohm A resistor has color bands orange, red, brown. It is ______. A. 232 ohms B. 3.2 Mohms C. 2.3 ohms D. 320 ohms - CORRECT ANSWER D: 320 ohms A circuit has one 500 ohm resistor in series with three 500 ohm resistors that are connected in parallel with each other. The total resistance would be ______. A. 666 ohms B. 167.7 ohms C. 750 ohms D. 1000 ohms - CORRECT ANSWER A: 666 ohms 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 maximum current the capacitor can allow D. is the same as the power factor - CORRECT ANSWER B: relates to the maximum voltage that should be applied to it Calculating the total capacitance of several capacitors connected in parallel ______. 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: A. the voltages equal to each other B. the reactance voltage of the capacitor or the inductor would be greater than the resistance voltage measurement C. the resistance voltage would be higher that the voltage across the inductor or the capacitor D. the supply voltage would be measured a ross the resistor and the voltage across the capacitor and across the inductor would measure 0V - CORRECT ANSWER A: the voltages 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 componets - CORRECT ANSWER D: there is a different level of current in the reactive componets than in the resistive components 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 of decrease - CORRECT ANSWER B: increase 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 of decrease - CORRECT ANSWER A: decrease A 50kHz AC voltage is applied to a 10mH inductor, its reactance at this frequency is: A. 3140 ohms B. 300 ohms C. 3100 ohms D. 500 ohms - CORRECT ANSWER A: 3140 ohms A 0.1microF capacitor in a circuit with a frequency of 100kHz applied has a reactance of A. 1.59 ohms B. 15.9 ohms C. 159 ohms D. 15.9 ohms - CORRECT ANSWER B: 15.9 ohms In a series circuit when the inductive reactances equal the capacitor reactances the circuit has ______ impedance. A. maximum B. double the inductors C. minimum D. no - CORRECT ANSWER C: minimum In a parallel circuit when the inductive reactances equal the capacitor reactances the circuit has ______ impedance. A. maximum B. double the capacitors C. minimum D. no - CORRECT ANSWER A: maximum 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 - CORRECT ANSWER C: the total of the inductive reactances in the circuit equal the total of all capacitive reactances ______ cells are prone to battery memory. A. zinc B. NiCad C. alkaline D. lithium - CORRECT ANSWER B: NiCad A conducting loop in motion through magnetic lines of flux has a current induced in it. The physical law that explains this is what? A. Lenz's law B. the law of inertia C. the Compton shift equation D. Kirchhoff's current law - CORRECT ANSWER A: Lenz's law An AC generator is also known as a ______. A. regulator B. alternator C. phasor D. slip ring - CORRECT ANSWER B: alternator Three- phase power is obtained from an AC generator by wiring the armature windings in a ______ or ______ configuration. A. alpha, beta B. treble, tri-phase C. polymorph, one-to-three D. delta, wye - CORRECT ANSWER D: delta, wye What element of a DC generator distinguishes it from an AC generator? D. 100 - CORRECT ANSWER A: 1 A variable capacitor's plates can open or close. As the plates open, capacitance: A. remains the same B. capacitors aren't made this way C. decrease D. increases - CORRECT ANSWER C: decreases an inductor with the same length of wire but whose turns are spaced further apart will have. A. less inductance B. more inductance C. equal inductance D. more mutual inductance - CORRECT ANSWER A: less inductance * CET unit 3 pic 4* What frequency will the parallel LC circuit below be resonant to? A. 100 MHz B. 159 Hz C. 6.28 MHz D. 1590 kHz - CORRECT ANSWER B: 159 Hz * CET unit 3 pic 5* Which formula is used to calculate reactance in the following schematic? A. Xc= 1/2piFC B. Xc= 2piFC C. Xc= R^2 + L^2 + C^2 D. Xc= 2piLFC - CORRECT ANSWER A: Xc= 1/2piFC An inductor in an electrical circuit: A. Causes current to lead voltage B. Opposes the flow of AC current C. Appears capacitive to AC current D. Appears as a short circuit to AC current - CORRECT ANSWER B: opposes the flow of AC current The term for the combination of resistance and reactance that restrict the flow of alternating current is. A. volt-amperes B. impedance C. susceptance D. power factor - CORRECT ANSWER B: impedance Is the value of a 500 picofarad capacitor and a .5 nanofarad capacitor identical? A. Yes B. No - CORRECT ANSWER A: yes In a generator, a DC voltage applied to the field windings controls the output level. A. true B. false - CORRECT ANSWER A: true Which of these is within tolerance for a resistor color coded red, black, red, gold. A. 1850 ohms B. 2150 ohms C. 1950 ohms D. 2250 ohms - CORRECT ANSWER C: 1950 ohms * CET unit 3 pic 5* Which one of the below is a common description of the filter shown below. A. bandpass B. low pass L C. low pass t D. high pass t - CORRECT ANSWER C: low pass t * CET unit 3 pic 6* What is the combined reactance of the two capacitors in series in the drawing below. A. approximately 1198 ohms B. approximately 265 ohms C. approximately 24 ohms D. approximately .00377 ohms - CORRECT ANSWER A: approximately 1198 ohms Which one of the below will cause a generator to produce DC voltage rather than AC voltage. A. brushes B. armature C. commutator D. field windings - CORRECT ANSWER C: commutator Total capacitance of capacitors connected in parallel is like: A. resistors connected in series B. capacitors connected in series C. resistors connected in parallel D. capacitors connected in parallel - CORRECT ANSWER A: resistors connected in series Which factor determines the value of a capacitor? A. area of the plates B. temperature coefficient of the dielectric C. inductance of the dielectric D. insulation covering - CORRECT ANSWER A: area of the plates A capacitor would most likely be rated: A. 5 watts B. 4 henrys C. 7 ohms D. 0.05 microfarad - CORRECT ANSWER D: 0.05 microfarad Which of these is most true of a PNP transistor? A. it will avalanche when the cutoff is reached B. it conducts equally well forward or backward C. A negative voltage will be applied to the collector D. the cathode must be heated to operate - CORRECT ANSWER C: A negative voltage will be applied to the collector An advantage a transistor has over a vacuum tube triode is: A. a triode cannot conduct from the cathode to the anode B. a transistor does not require an anode load C. a triode require grid bias D. a transistor normally has a longer life - CORRECT ANSWER D: a transistor normally has a longer life The most likely use of a transistor would be: A. to couple signals from one circuit to another B. to filter out unwanted signals C. as a regulator in power supplies D. to protect a circuit from excessive currents - CORRECT ANSWER A: to couple signals from one circuit to another Which of these would apply mostly to a "balun"? A. semiconductor B. impedance matching device C. integrated circuit D. over voltage protection - CORRECT ANSWER B: impedance matching device DIP refers to: A. Double integrated protection B. Dual ion positron C. Discrete icon positioner D. Dual inline package - CORRECT ANSWER D: duel inline package Diodes are marked with a band at the __________ end. A. Cathode B. Anode C. Center D. Base element - CORRECT ANSWER A: Cathode In testing a geranium diode, a forward-to-reverse ratio of 10-1 is indicative of a good diode. A. True B. False - CORRECT ANSWER B: False To properly bias a NPN silicon signal amplifier transistor, which voltages appear correct for a signal amplifier (SI)? A. E=0, B= +0.7, C= 10 B. E= 1, B= 2, C= +20 C. E= -1, B= -1.7 C= 9.3 D. E= 0, B= 0, C= 10 - CORRECT ANSWER A: E= 0, B= +0.7, C= 10 To properly bias a PNP transistor which voltages appear proper (SI)? A. E= 0, B= +1, C= +10 B. E= 1, B= 5, C= +20 C. E= -1, B= -1.7, C= -10 D. E= 0, B= 0, C= -10 - CORRECT ANSWER C: E= -1, B= 5, C= +20 In a transistor, which section is made very thin compared with the other two? A. Emitter B. Base C. Collector D. Each are exactly the same - CORRECT ANSWER B: Base Which part of a transistor carries the most current? A. Emitter B. Base C. Collector D. Base and emitter carry the same amount - CORRECT ANSWER A: Emitter The primary difference between a NPN and a PNP transistor is: A. physical shape B. DC voltages are reversed C. one is germanium and the other silicon D. the polarity of the power supply voltage - CORRECT ANSWER B: DC voltages are reversed Which transistor circuit normally produces the largest voltage gain? A. Common emitter B. Common base C. Common collector D. Transistor circuits produced current gain, not voltage gain - CORRECT ANSWER B: Common base Name one safety precaution taken before replacing a transistor. A. Remove power B. Remove transistor C. Short emitter to base to remove discharge voltage D. Put on rubber gloves for isolation - CORRECT ANSWER C: Short emitter to base to remove discharge voltage D. vacuum tube - CORRECT ANSWER C: silicon diode A four layer PN device is classified as a ______. A. diode junction B. transistor C. thyristor D. integrated circuit - CORRECT ANSWER C: thyristor How is a fuse installed in a circuit to insure proper operation? A. Parallel to the load B. In series with the load C. In any way possible D. At the ground point - CORRECT ANSWER B: In series with the load A negative temperature coefficient thermistor will: A. increase in resistance with temperature B. decrease in resistance with temperature C. have no change n resistance with heat or cold D. increase in resistance with higher voltage - CORRECT ANSWER B: decrease in resistance with temperature A NiMH battery cell, when charged, has a terminal voltage of: A. 2.1 volts B. 1.2 volts C. 5 volts D. 12 volts - CORRECT ANSWER B: 1.2 volts A thermocouple has an output in the range of: A. millivolts B. microvolts C. volts D. nanovolts - CORRECT ANSWER A: millivolts Germanium diodes: A. Have 0.3V forward voltage drop B. Are more often used in power supply circuits C. Are more tolerant of heat than silicon diodes D. Have 0.7V forward voltage drop - CORRECT ANSWER A: Have 0.3 forwarded voltage drop A MOSFET: A. has low input impedance B. is also called bi-polar transistor C. amplifies input current changes D. has high input impedance - CORRECT ANSWER D: has high input impedance Integrated Circuit packages: A. save energy B. reduce space requirements C. require more cooling D. have radiation leakage - CORRECT ANSWER B: reduce space requirements * CET unit 4 pic 1* Which of the silicon diodes below will conduct, given the voltages applied. A. A B. B C. C D. D - CORRECT ANSWER A: A if the gate voltage level, that turns an active SCR on, drops below the trigger point, while anode and cathode voltages are maintained, what will occur? A. the SCR turns off B. The SCR stays on C. The SCR turns on D. An output pulse is generated - CORRECT ANSWER B: The SCR stays on * CET unit 4 pic 2* The transistor configuration shown here is: A. PNP B. NPN C. MOSFET D. FET - CORRECT ANSWER B: NPN What is the effect on a varactor (varicap) when the reverse bias voltage is increase? A. capacitance decreases and the tuned frequency increases B. Capacitance increases and the tuned frequency decreases C. The diode conducts more D. The signal waveform becomes distorted - CORRECT ANSWER A: Capacitance decreases and the tuned frequency increases An electronic power supply may be designed to ______. A. change DC to DC B. Change AC to AC C. change the frequency D. changes AC to DC E. All the above answers are correct - CORRECT ANSWER E: All the above answers are correct In the normal layout (block diagram) of a DC power supply the order of the sections would be: A. Filter, Rectifier, Regulator B. Rectifier, Filter, Regulator C. Rectifier, Regulator, Filter D. None of the above - CORRECT ANSWER B: Rectifier, Filter, Regulator A. transconductance of the vacuum tube B. AC plate resistance of the vacuum tube C. amplification factor of the vacuum tube D. forward current transfer ratio of the vacuum tube - CORRECT ANSWER C: amplification factor of the vacuum tube A class AB amplifier will allow output current to flow for approximately ______ of the input signal. A. 100 degrees B. 180 degrees C. 280 degrees D. 360 degrees - CORRECT ANSWER C: 280 degrees The formula [(u*RL)/(RL + rD)] is used to calculate: A. forward transfer current ratio of the JFET B. voltage gain of the JFET amplifier C. amplification factor of the JFET D. transconductance of the JFET - CORRECT ANSWER B: voltage gain of the JFET amplifier 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 - CORRECT ANSWER B: common-cathode , D: common- source , G: common-emitter Given the following information about a common-emitter amplifier, a 0.01Vp-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 2.5 mA through out 2.2 kohm load. Determine the dynamic current gain. A. 10 B. 20 C. 50 D. 100 - CORRECT ANSWER C: 50 Which of the following amplifier configuration(s) would you likely find being used in a linear push-pull arrangement? A. Class A B. Class B or AB C. Class C D. All of the above - CORRECT ANSWER B: Class B or AB If a 1.02 MHz signal and a 1.475 MHz signal are fed to a common-emitter transistor amplifier biased to operate in a non-linear manner we would expect to see which of the following frequencies in the output? A. 455 kHz B. 1.02 MHz C. 1.475 MHz D. 2.495 MHz E. All of the above - CORRECT ANSWER E: All of the above 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 - CORRECT ANSWER B: Selectivity *CET chap 12 pic 1* The provided picture illustrates ______. A. a non-active de-modulator B. an RF amplifier being used as a mixer C. a common-emitter amp used as a limiter D. an active detector - CORRECT ANSWER D: an active detector Which of the following circuits can be used to recover audio from an IF in a FM receiver? A. Phase Locked Loop B. Class A, common-gate JFET amplifier C. Push-pull, class A JFET amplifier D. Mixer - CORRECT ANSWER A: Phase Locked Loop * CET unit 5 pic 1* In the drawing, what voltage is present at point A? A. 13 V B. 19.3 V C. 14.9 V D. 12.3 V - CORRECT ANSWER D: 12.3 V *CET unit 5 pic 2* The output (A) of the regulator circuit should be about: A. 13.8 VDC B. 9.2 VDC C. 10 VDC D. 8.5 VDC - CORRECT ANSWER D: 8.5 VDC *CET unit 5 pic 3* In the circuit , to reproduce the square wave input more faithfully at the output: E. Faraday Commission of Communications - CORRECT ANSWER C: Federal Communications Commission What is not a part of a superheterodyne radio receiver? A. Intermediate Frequency Circuit B. Radio Frequency Circuit C. Audio Frequency Circuit D. Audio Radiation Resistance CIrcuit E. Mixer Circuit - CORRECT ANSWER D: Audio Radiation Resistance Circuit Match up the correct items: A. RF 1. Amplitude Modulation B. AF 2. Weather (no chapter reference) C. IF 3. Audio Frequency D. FM 4. Radio Frequency E. AM 5. Intermediation Frequency F. WX 6. Frequency Modulation - CORRECT ANSWER A-4, B-3, C-5, D-6, E-1, F-2 Which part of a superheterodyne receiver rectifies the RF carrier? A. AF circuit B. Detector Circuit C. Low Pass Filter D. Modulation Circuit E. RF Circuit - CORRECT ANSWER B: Detector Circuit How long should a 1/4 wavelength vertical antenna be that is designed for operation on 146 MHz? A. 1.1 Feet B. 1.6 Feet C. 1.9 Feet D. 2.3 Feet E. 3.2 Feet - CORRECT ANSWER B: 1.6 Feet What is the common impedance of radio communication and television coaxial cable respectively? A. 35 and 55 ohms B. 50 and 75 ohms C. 60 and 93 ohms D. 77 and 98 ohms E. 80 and 100 ohms - CORRECT ANSWER B: 50 and 75 ohms Which layer of the ionosphere absorbs high frequency radio waves during daylight hours? A. D layer B. E layer C. F layer D. F1 layer E. F2 layer - CORRECT ANSWER A: D layer Which style of antenna radiates in opposite directions, with a pattern resembling a figure 8? A. Omni directional B. Yagi C. Dipole D. Cubical Quad E. Log-Periodic - CORRECT ANSWER C: Cubical Quad What frequency and is an average AM commercial broadcast radio capable of receiving? A. 535 to 1700 kHz B. 630 to 1810 kHz C. 810 to 2120 kHz D. 2.5 to 3.10 MHz E. 3.8 to 4.2 MHz - CORRECT ANSWER A: 535 to 1700 kHz Why is RF safety important? A. To ensure maximum power output at all times B. Always assuring variable tuning capability C. Capability to receive distant radio stations D. To limit human exposure to RF for health reasons E. Maintain adequate FCC bandwidth spacing - CORRECT ANSWER D: To limit human exposure to RF for health reasons What is the process of imposing intelligence on a carrier wave? A. Extrapolation B: Modulation C. Transmission D. Oscillation - CORRECT ANSWER B: Modulation The basic formula for wavelength is L=wavelength, v= velocity, f=frequency. A. L=v/f B. v=L/r C. L=f/v D. L=r/v - CORRECT ANSWER A: L=v/f Flexible coaxial transmission lines are ideal for what frequencies? A. MHz only B. kHz only C. Above GHz D. Below GHz - CORRECT ANSWER D: Below GHz Standing waves occur on a transmission line when there is a /an ______ between the transmission line and the load A. impedance match B. impedance mismatch C. resistance match D. capacitive reactance match - CORRECT ANSWER B: impedance mismatch D. CCS - CORRECT ANSWER D: CCS A CLEC is _______. A. a cable TV company B. the incumbent telephone company C. a wireless provider D. either a or c - CORRECT ANSWER D: either a or c The maximum bit rate available on a T-1 transmission system is: A. 56 kbps B. 64 kbps C. 1.544 Mbps D. 2.4 Gbps - CORRECT ANSWER C: 1.544 Mbps A call between area codes is __________. A. Local long distance B. Inter-LATA C. Intra-LATA D. Toll free - CORRECT ANSWER B: Inter-LATA the device that causes the phase change between mouth and ear audio in a telephone subscriber unit is the: A. hybrid coil B. delay line C. hook switch D. transmitter - CORRECT ANSWER A: hybrid coil The 2nd generation digital wireless access technology that uses code patterns to operate user's is: A. AMPS B. TDMA C. GSM D. CDMA - CORRECT ANSWER D: CDMA A Logic 1, for a TTL device is _______. A. more than 1 volt B. more than 1.5 volt C. more than 2 volts D. more than 3.5 volts - CORRECT ANSWER C: more than 2 volts A Logic 1, for a CMOS device connected to a 5 V supply is ______. A. more than 1 volt B. more than 1.5 volt C. more than 2 volt D. more than 3.5 volt - CORRECT ANSWER D: more than 3.5 volt A green light usually indicates _____. A. a logic high B. a logic low C. a TTL logic level D. a CMOS device - CORRECT ANSWER B: a logic low Another name for an astable multivibrator is ______. A. Latch B. One shot C. Free running D. Mono - CORRECT ANSWER C: Free running The number 12 in decimal is _____ in binary. A. 1200 B. 1100 C. 1010 D. 1011 - CORRECT ANSWER B: 1100 The number 25 in octal is ______ in binary. A. 010101 B. 011001 C. 110111 D. 100101 - CORRECT ANSWER A: 010101 The three Basic Logic gates are _____. A. AND, OR, NAND B. AND, OR, NOT C. NAND, NOR, Inverter D. NAND, XOR, NOR - CORRECT ANSWER B: AND, OR, NOT The NAND gate is sometimes called ______. A. all or nothing B. any but not all C. universal D. inverter - CORRECT ANSWER C: universal The Boolean expression Y= A + B (with line over A + B) represents _______. A. And B. NAND C. OR D. NOR - CORRECT ANSWER D: NOR The difference between midterm and max term is ________. A. minterm, Y = 1, Least # of gates is AND B. maxterm, Y = 1, Least # of gates is OR C. minterm Y = 0, Least # of gates is OR D. maxterm, Y = 0, Least # of gates is AND - CORRECT ANSWER D: maxterm, Y = 0, Least # of gates is AND A. The pharmacist B. The technician C. The operator D. The operator's friend - CORRECT ANSWER C: The operator Before beginning to troubleshoot, what should you do? A. verify the failure B. call your friend C. disassemble the equipment D. divide and conquer - CORRECT ANSWER A: verify the failure A short allows for an increase of current and ______. A. voltage B. resistance C. heat D. trouble - CORRECT ANSWER C: heat What is the oldest piece of troubleshooting equipment a technician has? A. Oscilloscope B. Analog Volt Meter C. Galvanometer D. Five Senses - CORRECT ANSWER D: Five Senses Which of the following word(s) is in the acronym: TEST? A. Time B. Ego C. Spectral Efficiency D. Technical Education - CORRECT ANSWER D: Technical Education What is the name of the diagram that shows all the general cable connections of a piece of equipment? A. Schematic diagram B. Block diagram C. Interconnect diagram D. Parts list - CORRECT ANSWER C: Interconnect diagram Diagnosing component failures requires the use of a/an __________. A. Schematic diagram B. Block diagram C. Interconnect diagram D. Parts list - CORRECT ANSWER A: Schematic diagram A repair is only as good as ________. A. the test equipment B. the equipment brand C. the part replacement D. the soldering - CORRECT ANSWER D: the soldering Before returning the equipment to the customer it is important that you _______. A. verify operation B. prepare the bill C. hide extra screws D. call the customer - CORRECT ANSWER A: verify operation What is the most important service you provide? A. Technical expertise B. Equipment repair C. Intelligence D. Customer service - CORRECT ANSWER D: Customer service an average reading AC voltmeter _________. A. displays the average AC voltage value B. converts to a peak reading before displaying the voltage C. multiples the average value by 1.111 before displaying the voltage D. multiplies the average value by 0.636 before displaying the voltage - CORRECT ANSWER C: multiplies the average value by 1.111 before displaying the voltage Use of a x10 scope probe instead of a direct probe: A. reduces circuit loading B. increases the effective input impedance C. decreases the signal to the scope D. all of the above - CORRECT ANSWER D: all of the above 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 - CORRECT ANSWER B: Applied to the Z-axis To accurately measure a resistance across a transistor's emitter-base junction, use a ______. A. higher ohmmeter range than you normally would B. lower ohmmeter range than you normally would C. high ohms function D. low ohms function - CORRECT ANSWER D: low ohms function an inductor shorted turn can be detected reliably using a ________. A. leakage test B. ringer rest C. AC impedance bridge D. all of the above - CORRECT ANSWER B: ringer test 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 B. results in a poor mechanical connection C. results in a poor mechanical and electrical connection D. is OK so long as the solder doesn't migrate away from the joint - CORRECT ANSWER A: results in a poor electrical connection Which device is capable of causing magnetic or inductive damage to electronics devices? A. pencil soldering iron B. high wattage resistance soldering tin C. solder suckers & rubber vacuum bulbs D. soldering gun - CORRECT ANSWER D: soldering gun To remove solder from a joint using copper braid: A. heat the joint then quickly dip the cold braid into the melted solder and remove B. heat the component leads at the joint first, then the braid C. wrap the braid around the soldering iron tip and while hot, wipe off solder from the joint D. touch the joint with the braid, heat it and let the solder wick up the braid - CORRECT ANSWER D: touch the joint with the braid, heat it and let the solder wick up the braid The best way to remove an IC chip which is soldered into a PC board is to: A. use a desoldering adapter tip which heats all pins simultaneously B. use wick and remove all solder from the pins - pry loose C. heat each pin sequentially while prying up on the IC D. use a solder-sucker to remove all pin solder - CORRECT ANSWER A: use desoldering adapter tip which heats all pins simultaneously Surface mount components do not require mechanical bonding because: A. the components are so small the solder connection holds them adequately B. their sockets provide adequate bonding C. their leads always "hook" onto the opposite side of the PC board D. special strength solder is used on SM boards - CORRECT ANSWER A: the components are so small the solder connection holds them adequately Record keeping is needed for which activities? A. customer service B. warranty service validation C. Business planning D. all of the above - CORRECT ANSWER D: all of the above A technician should _____. A. understand the record keeping process B. let administrative staff do all record keeping C. make multiple coped of all records they file D. allow the client to fill in their own forms - CORRECT ANSWER A: understand the record keeping process 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 - CORRECT ANSWER B: client invoices are properly processed Keeping a record for customer service purposes ensures that_______. A. parts inventory levels are maintained B. the technician can verify billable hours C. follow-up. service can be provided D. none of the above - CORRECT ANSWER A, B, or C A service or repair ticker 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 - CORRECT ANSWER A: information about The Who, what, when, where, why, and how regarding the service call Forms should be filled in using ___. a. pencil b. erasable ink c. a black ink ballpoint pen d. a blue ink ballpoint pen - CORRECT ANSWER C: a black ink ballpoint pen A personal field notebook______. A. can help the technician keep track of special requests and reference material B. can be used to issue an on the spot invoice or receipt C. can be shared by other technicians on a single shift D. is a book of forms provided by the company - CORRECT ANSWER A: can help the technician keep track of special requests and reference material The formula for calculating productivity is ________. A. B(T)=P(100) B. B(T)=P(100)=P% C. P/T(B)=P% D. P(T)=P(100) - CORRECT ANSWER B: B(T)=P(100)=P% The 30-30-30 rule refers to: A. billable hours, schedules hours, and productivity B. wages, overhead expenses, productivity C. wages, scheduled hours, overhead expenses D. wages, overhead expenses, re-investment - CORRECT ANSWER D: wages, overhead expenses, re-investment The safest accessory item for a tie is: C. consider and note objectives D. make table of contents - CORRECT ANSWER C: consider and note objectives oscillators use quartz crystals that generate output by the: A. phase-shift effect B. Piezoelectric effect C. Doppler effect D. Avalanche (or Zener) effect - CORRECT ANSWER B: Piezoelectric effect Analog telephone lines have what DC voltage level across the tip and ring when off-hook? A. 110 VDC B. 6 VDC C. -48 VDC D. depends on length of line - CORRECT ANSWER C: -48 VDC 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 - CORRECT ANSWER D: compared to frees place velocity Cables of different impedances may be combined for runs. A. True B. False - CORRECT ANSWER B: false The bandwidth of a standard definition analog TV A. 6 MHz B. 16 MHz C. 24 MHZ D. 88 MHZ - CORRECT ANSWER A: 6 MHZ What radio receiver section determines the radio's inherent noise level? A. RF B. Mixer C. IF D. Detector - CORRECT ANSWER A: RF Carbon microphones are much like variable: A. Capacitors B. Resistors C. Thermistors D. Inductors - CORRECT ANSWER B: Resistors In telecommunications work, ______ is replacing twister pair cabling. A. microwave B. wireless C. fiber optics D. both b and c - CORRECT ANSWER D: both b and c A length of coaxial cable, used for computers, radios, 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? A. the cable is partially shorted B. the cable is completely open C. that reading is correct for 50 ohm impedance RF cables D. that reading is lower than 72 ohms for video cables - CORRECT ANSWER A: the cable is partially shorted Waveguides are not utilized at HF of 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 - CORRECT ANSWER C: Large waveguide dimensions required at lower frequencies are not practical *cet unit 6 pic 1* The item shown below is a (no chapter reference): A. Mini UHF B. PL-259 C. BNC D. N - CORRECT ANSWER C: The +5V level of a Tel digital signal is called a logical: A. 0 or low B. 0 or high C. 1 or low D. 1 or high - CORRECT ANSWER D: 1 or high 165(decimal) covered to binary would be: A. 01110100 B. 10001111 C. 10010101 D. 10100101 - CORRECT ANSWER D: 10100101 The 1 in binary number 1000000 carries a decimal weight of: A. 32 B. 16 C. 64 D. 128 - CORRECT ANSWER C: 64 Which one of the following integrated circuit or semiconductor devices normally requires the most careful handling to avoid damage by static electricity? A. MOS A three input NAND has two high inputs and a low input. The output would be: A. high B. low C. not enough information D. can be neither high or low - CORRECT ANSWER A: high Adding the binary numbers 110111 and 001100 will give which one of the results below? A. 0000101 B. 0111101 C. 1000011 D. 1111011 - CORRECT ANSWER C: 1000011 A circle is obtained on the scope when: A. two sine waves that are 90 degrees out-of-phase fed to the vertical and horizontal inputs B. two sawtooth waves, in phase, are fed to the vertical and horizontal inputs C. a sine wave and a sawtooth wave are compared o the scope screen D. two in-phase sine waves are fed to the horizontal and the vertical inputs - CORRECT ANSWER A: two sine waves that are 90 degrees out-of-phase fed to the vertical and horizontal inputs Which frequency is most commonly used for audio troubleshooting? A. 1000 kHz B. 0.1 kHz C. 1 Hz D. 1 kHz - CORRECT ANSWER D: 1 kHz Why is a coupling capacitor used when troubleshooting with signal injection? A. improve frequency response B. block DC level present C. prevent loading of the circuit D. provide a correct impedance match - CORRECT ANSWER B: block DC level present Which would be the likely cause of hum in an amplifier, but only present when the CD position is selected? A. bad filter capacitor in the power supply B. open ground in the CD power amplifier C. bad shielded cable from the CD player D. defective speaker - CORRECT ANSWER C: bad shielded cable from the CD player A stereo amplifier has sever hun whether CD, AUX, FM or AM RADIO are selected. What is the most likely cause? A. volume control shorted B. defective output transistor grounding C. power cord polarity wrong D. power supply filtering - CORRECT ANSWER D: power supply filtering Which of the below will cause distortion at high audio levels in an amplifier system? A. scratchy tone control B. running speaker voice coil C. bias on a transistor D. bass-boost control on - CORRECT ANSWER B: running speaker voice coil The Y axis of an oscilloscope is: A. brightness B. intensity C. focus D. vertical - CORRECT ANSWER D: vertical 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 capacitors should be: A. ignored B. disconnected C. discharged to chassis ground with a suitable resistor D. isolated with a non-conductive cover - CORRECT ANSWER C: discharged to chassis ground with a suitable resistor A dual-trace scope has: A. two focus controls B. two sets of position controls C. two vertical inputs D. both b and c - CORRECT ANSWER D: both b and c 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 - CORRECT ANSWER D: decreases circuit loading that a direct probe presents A voltmeter that converts AC to DC by rectifying the voltage, would be least accurate measuring what types of alternating voltages? A. pulses B. sine waves C. peak voltages D. UHF signals - CORRECT ANSWER A: pulses When connecting an analog voltmeter into a DC circuit, what would be observed? A. RMS rating of meter B. loading of meter