ETA/CET Exam Questions & Answers Solved 100%

What is impedance? - Answer The resistance of a component at a given frequency A two terminal device that conducts in only one direction. - Answer Diode Insulating board containing conductive tracks for circuit connections. - Answer Printed Circuit Board An electrical device used to store electrical charge. - Answer Capacitor When did the ETA initiate renewal? - Answer 1996 all ETA certifications require the passage of the associate CET exam? - Answer False to qualify for master CET status, the examinee must attain a score of 85% on each separate exam? - Answer False The coaxial cable leading to a cable TV is a 75 ohm transmission line. If you use 10Base2 coax cable for networking, that is a _____ ohm transmission line. - Answer 50 an associate CET cannot attempt one of the specialty exams? - Answer false renewal requires payment of a fee and retesting or providing at least 40 hours of upgrade training within a 4 year period? - Answer true a worker may become certified by ETA as a CST without also becomming certified as a CET? - Answer true B+, or supply voltages in electronics products are considered to be: - Answer +12V to 300V DC leakage current in an electronic product, between either of the AC power cord conductors and the chassis or any other exposed metal parts should not exceed: - Answer 500 microamps the associate CET exam may be taken after the journeyman exam? - Answer false shaded components on electronic schematics mean: - Answer only exact replacement parts may be used ingested solder fumes or particles_____ - Answer are toxic second degree skin burns should ______ - Answer not be treated with ice and bandage pack ESD and static discharge is most destructive to: - Answer CMOS semiconductors if you have never recieved formal training and practiced cpr on a person or dummy, in the event of finding a fellow worker not breathing, you_________. - Answer should not attempt it, but call for help when working at heights above 6 feet, a _____ is required by OSHA rules. - Answer full body harness attached to a lanyard which prevents more than a 6' drop. What is meant by "transformer action"? - Answer The transfer of energy from one circuit to another circuit by electromagnetic induction residual voltage is associated with ______. - Answer charge retained by capacitors. What does the acronym ESD stand for? - Answer Electrostatic Discharge Current amounts between ______ and _____ can be lethal. - Answer 100mA, 200mA What is the number one concern in regards to electrical safety? - Answer Shock Bohr's Atomic Model consists of what three components? - Answer Protons, neutrons and electrons Electrons are arranged in _____ around a nucleus. - Answer shells What are three types of materials used in electronics? - Answer Conductors, semi-conductors and insulators In the United States there are five common classifications of fires, which are: - Answer A, B, C, D, K. Coulomb's Law describes the forces of attraction or repulsion between electrical charges, which are ______________ to the product of the charges ______________ to the distance between them. - Answer directly proportional, inversely proportional The magnetic field that surrounds a magnet can best be described as invisible lines of force, and are commonly referred to as: - Answer lines of flux. An analog multimeter (AMM) checks for: - Answer voltage, current and resistance. An oscilloscope with two vertical inputs, is commonly referred to as a _______ oscilloscope. - Answer dual-trace Voltage or potential difference is the measure of potential energy between two points in a circuit and is commonly referred to as: - Answer voltage drop. What components value is measured in millihenries? - Answer Inductor Ohm's Law characterizes the relationship between: - Answer power, resistance, current and voltage. A resistor has three color bands of red, brown and brown. What is the ohmic value of this resistor? - Answer 210 Ohms Ohm's Law states that resistance is calculated by voltage divided by current. Using Ohms law, how do you determine power? - Answer Voltage times current Total resistance in a series circuit equals: - Answer the sum of all the resistor values within the circuit. If a series circuit has three resistors valued at 10k Ohms, 15k Ohms and 20k Ohms, with a voltage source of 15V, the total current will be_____. - Answer 333.33uA Current in a parallel circuit is: - Answer inversely proportional to the circuits resistance. With three 2.5k resistors and one 3.4k resistor in parallel, the total resistance is: - Answer 669.29 Ohms With one series 8 Ohm resistor connected to two in-parallel resistors, 20 and 30 ohms respectively, what is the total resistance (Rt)? - Answer 20 Ohms Given a battery rated at 350 ampere-hours how many hours will the battery be able to provide 7 amperes? - Answer 50 The basic properties associated with alternating voltage and current are: - Answer frequency, period, wavelength and amplitude. In an inductor/coil inductance varies as the _______ of the number of turns. - Answer Square rules describing the fire or toxicity retardant types of cabling which may be installed in buildings is contained in: - Answer NEC article 770 Two basic uses for transformers are: - Answer signal matching and power supplies. What are the three basic parts of a transformer? - Answer Primary winding, secondary winding and core The time required to charge a capacitor to 63 percent is known as: - Answer a time constant. Calculate the capacitive reactance for 440 Hz and 9μF. - Answer 40.21 Ohms 6.28 x frequency x capacitor 1/the sum from above 6.28 x 440 = 2763.2 2763.2 x .000009 = .0248688 1/.0248688 = 40.21 In a resistive-capacitive circuit the vector line relationship shows two lines perpendicular to each other. What is the phase relationship? - Answer 90 degree In a capacitive circuit, what is the voltage and current relationship? - Answer Voltage lags ELI the ICE man!!! ELI Inductive circuit...... Voltage arrives before Current ICE Capacitive circuit... Current arrives before Voltage When the frequency of an applied voltage is increased the capacitive reactance of a circuit will: - Answer decrease What is the difference between calculating impedance for a series AC circuit and a parallel AC circuit? - Answer A series impedance calculation is derived from resistance and reactance, while parallel impedance is calculated with resistive and reactive current divided into the source voltage Each type of coaxial cable is designed with_____________, which is dependent on materials and dimensions used. - Answer characteristic impedance A coaxial cable's velocity of propagation factor depends on what two factors? - Answer Dielectric constant and permeability In a series resistive and reactive circuit what formula is used to find total impedance? - Answer Z =sqrt( R2 + X2) Silicon diodes have an approximate voltage drop of: - Answer .7V In regards to AWG standards, which gauge of wire has a bigger crosssectional area? A. 16 AWG B. 18 AWG C. 20 AWG D. 24 AWG - Answer A 16 AWG What is a primary advantage of a FET when compared to the bipolar transistor? - Answer High input impedance Zener diodes are designed to operate in the _____ bias region. - Answer reverse When compared to a JFET, the base of a bipolar transistor is similar to what element of the JFET? - Answer Gate A MOSFET is comprised of what four elements? - Answer Gate, source, drain and substrate How many PN junctions does a Unijunction transistor have? - Answer One A thyristor is a semiconductor with _____ layers that form ____ PN junctions. - Answer 4,3 If a signal decreases by 3 dB, how much power is lost? - Answer 50% -3dBm is equal to how many milliwatts? - Answer .5mW The formula to calculate dBm from mW is: - Answer 10 log10( P / 1mW) The split capacitors in a Colpitts oscillator provide: - Answer regenerative feedback. Why are crystal oscillators preferred over other types of oscillators? - Answer When keeping frequency error or drift at a minimum is important Why is a differentiator used at the input of a flip-flop? - Answer To produce a sharp spike What is one way to minimize parasitic oscillations? - Answer Place a swamping resistor across the transformer master CET is lifetime and does not require re certification? - Answer true In a class 'C'collector: - Answer collector current flows for less than one half cycle of the input signal. (180°) What is the radix of the hexadecimal number system? - Answer 16 What is the hexadecimal equivalent of the decimal number 622? - Answer 26E What is the decimal sum of 10010 and 11001? - Answer 43 What does the acronym EAROM stand for? - Answer Electrically Alterable Read Only Memory What are three processor functions of a CPU? - Answer Arithmetic logic, interfacing and control If an oscilloscopes TIME/DIV is set at .2 microseconds, and the width of the pulse measured is at 8 divisions on the scope graticule, what is the pulse width? - Answer 1.6 microseconds Why is flux used when soldering? - Answer To prevent the formation of metal oxides at extreme temperatures Lead and tin solder at a respective percentage of 63/37 melts at ______: - Answer 361 degrees F What four methods are used in coupling amplifier stages? - Answer Direct, RC, impedance and transformer coupling What formula is used to calculate output voltage of a Difference operational amplifier? - Answer Vout = (Rf/Rin)(V2 - V1) When calculating power levels(in db), which formula is correct? - Answer dB=10*log(P1/P2) Due to the configuration of the filtering components, the ability of a_____ type filter to remove ripple voltage is superior to that of either the _______ or ________ filter. - Answer Pi, capacitive, inductive What type of diagram shows electrical connections and functions of a specific circuit arrangement? - Answer Schematic Opening and closing vinyl envelopes used to carry work instructions, with 10-20% relative humidity, electro-static voltages can reach as high as: - Answer 7,000V What is the modulus of a five-stage binary counter? - Answer 32 electron has a ______ charge - Answer negative What is the preferred method for removing solder from a component attached to a circuit card assembly (CCA)? - Answer Motorized vacuum extraction To overcome noise, distortion and cost of maintenance in frequency division multiple systems, ________ systems were developed. - Answer time-division multiplex What does LEC stand for? - Answer Local exchange carrier Circuit switch networks maintain only _____ path(s) for the duration of the call. - Answer one What are the three fundamental types of wireless access technologies? - Answer FDMA, CDMA and TDMA In the kinescope, the ________ intensity of an electron beam from an electron gun is modulated in accordance with the ________ variations of signals received by a control electrode, or modulator. - Answer current, amplitude A vertically polarized antenna has a magnetic field that is at a _____ angle to the axis of the antenna. - Answer 90 degree The 4-meter frequency band is also known as the _____ band. - Answer 70 MHz In a common anode, seven-segment LED display, an individual LED will light if a negative voltage is applied to what element? - Answer Cathode a cell with an EMF of 1.8V delivers a current of 2.5A through an external resistance of 0.6ohms. calculate the internal resistance: 1.8V/2.4A=.72ohm -the .6ohm resistance known - Answer .12 ohms RMS of a waveform is: - Answer .707 of peak voltage the RMS value of a 60Hz sine wave voltage is 120V. what is peak to peak? - Answer 339.4V peak voltage from RMS (of a wave form) - Answer 1.414 x RMS a sine wave has a frequency of 60Hz, find the period - Answer 16.6ms (1 divided by the frequency) to find period (time) from frequency - Answer 1/F to find frequency from time (period) - Answer 1/T a capacitor in an electrical circuit ________ a ________ of voltage - Answer opposes/change