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Amateur Radio Question PoolsNew! View the differences between the 2008 Extra question pool and the previous pool. Amateur Extra Class Question PoolPrev 1 2 3 4 5 6 7 8 9 0 NextE5A01 What can cause the voltage across reactances in series to be larger than the voltage applied to them? Resonance Capacitance Conductance Resistance E5A02 What is resonance in an electrical circuit? The highest frequency that will pass current The lowest frequency that will pass current The frequency at which capacitive reactance equals inductive reactance The frequency at which power factor is at a minimum E5A03 What are the conditions for resonance to occur in an electrical circuit? The power factor is at a minimum Inductive and capacitive reactances are equal The square root of the sum of the capacitive and inductive reactance is equal to the resonant frequency The square root of the product of the capacitive and inductive reactance is equal to the resonant frequency E5A04 When the inductive reactance of an electrical circuit equals its capacitive reactance, what is this condition called? Reactive quiescence High Q Reactive equilibrium Resonance E5A05 What is the magnitude of the impedance of a series R-L-C circuit at resonance? High, as compared to the circuit resistance Approximately equal to capacitive reactance Approximately equal to inductive reactance Approximately equal to circuit resistance E5A06 What is the magnitude of the impedance of a circuit with a resistor, an inductor and a capacitor all in parallel, at resonance? Approximately equal to circuit resistance Approximately equal to inductive reactance Low, as compared to the circuit resistance Approximately equal to capacitive reactance E5A07 What is the magnitude of the current at the input of a series R-L-C circuit at resonance? It is at a minimum It is at a maximum It is DC It is zero E5A08 What is the magnitude of the circulating current within the components of a parallel L-C circuit at resonance? It is at a minimum It is at a maximum It is DC It is zero E5A09 What is the magnitude of the current at the input of a parallel R-L-C circuit at resonance? It is at a minimum It is at a maximum It is DC It is zero E5A10 What is the relationship between the current through a resonant circuit and the voltage across the circuit? The voltage leads the current by 90 degrees The current leads the voltage by 90 degrees The voltage and current are in phase The voltage and current are 180 degrees out of phase E5A11 What is the relationship between the current into (or out of) a parallel resonant circuit and the voltage across the circuit? The voltage leads the current by 90 degrees The current leads the voltage by 90 degrees The voltage and current are in phase The voltage and current are 180 degrees out of phase E5A12 What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 1.8 MHz and a Q of 95? 18.9 kHz 1.89 kHz 189 Hz 58.7 kHz E5A13 What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150? 211 kHz 16.5 kHz 47.3 kHz 21.1 kHz E5A14 What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 14.25 MHz and a Q of 150? 95 kHz 10.5 kHz 10.5 MHz 17 kHz E5A15 What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 21.15 MHz and a Q of 95? 4.49 kHz 44.9 kHz 22.3 kHz 222.6 kHz E5A16 What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118? 22.3 kHz 76.2 kHz 31.4 kHz 10.8 kHz E5A17 What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 14.25 MHz and a Q of 187? 22.3 kHz 10.8 kHz 76.2 kHz 13.1 kHz E5A18 What is the resonant frequency of a series RLC circuit if R is 47 ohms, L is 50 microhenrys and C is 40 picofarads? 79.6 MHz 1.78 MHz 3.56 MHz 7.96 MHz E5A19 What is the resonant frequency of a series RLC circuit if R is 47 ohms, L is 40 microhenrys and C is 200 picofarads? 1.99 kHz 1.78 MHz 1.99 MHz 1.78 kHz E5A20 What is the resonant frequency of a series RLC circuit if R is 47 ohms, L is 50 microhenrys and C is 10 picofarads? 3.18 MHz 3.18 kHz 7.12 kHz 7.12 MHz E5A21 What is the resonant frequency of a series RLC circuit if R is 47 ohms, L is 25 microhenrys and C is 10 picofarads? 10.1 MHz 63.7 MHz 10.1 kHz 63.7 kHz E5A22 What is the resonant frequency of a series RLC circuit if R is 47 ohms, L is 3 microhenrys and C is 40 picofarads? 13.1 MHz 14.5 MHz 14.5 kHz 13.1 kHz E5A23 What is the resonant frequency of a series RLC circuit if R is 47 ohms, L is 4 microhenrys and C is 20 picofarads? 19.9 kHz 17.8 kHz 19.9 MHz 17.8 MHz E5A24 What is the resonant frequency of a series RLC circuit if R is 47 ohms, L is 8 microhenrys and C is 7 picofarads? 2.84 MHz 28.4 MHz 21.3 MHz 2.13 MHz E5A25 What is the resonant frequency of a series RLC circuit if R is 47 ohms, L is 3 microhenrys and C is 15 picofarads? 23.7 MHz 23.7 kHz 35.4 kHz 35.4 MHz E5B03 What is the term for the time it takes for a charged capacitor in an RC circuit to discharge to 36.8% of its initial value of stored charge? One discharge period An exponential discharge rate of one A discharge factor of one One time constant E5B04 The capacitor in an RC circuit is charged to what percentage of the supply voltage after two time constants? 36.8% 63.2% 86.5% 95% E5B05 The capacitor in an RC circuit is discharged to what percentage of the starting voltage after two time constants? 86.5% 63.2% 36.8% 13.5% E5B06 What is the time constant of a circuit having two 100-microfarad capacitors and two 470-kilohm resistors all in series? 47 seconds 101.1 seconds 103 seconds 220 seconds E5B07 What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors all in parallel? 47 seconds 101.1 seconds 103 seconds 220 seconds E5B08 What is the time constant of a circuit having a 220-microfarad capacitor in series with a 470-kilohm resistor? 47 seconds 80 seconds 103 seconds 220 seconds E5B09 How long does it take for an initial charge of 20 V DC to decrease to 7.36 V DC in a 0.01-microfarad capacitor when a 2-megohm resistor is connected across it? 0.02 seconds 0.08 seconds 450 seconds 1350 seconds E5B10 How long does it take for an initial charge of 20 V DC to decrease to 0.37 V DC in a 0.01-microfarad capacitor when a 2-megohm resistor is connected across it? 0.02 seconds 0.08 seconds 450 seconds 1350 seconds E5B11 How long does it take for an initial charge of 800 V DC to decrease to 294 V DC in a 450-microfarad capacitor when a 1-megohm resistor is connected across it? 0.02 seconds 0.08 seconds 450 seconds 1350 seconds E5C01 What type of graph can be used to calculate impedance along transmission lines? A Smith chart A logarithmic chart A Jones chart A radiation pattern chart E5C02 What type of coordinate system is used in a Smith chart? Voltage circles and current arcs Resistance circles and reactance arcs Voltage lines and current chords Resistance lines and reactance chords E5C03 What type of calculations can be performed using a Smith chart? Beam headings and radiation patterns Satellite azimuth and elevation bearings Impedance and SWR values in transmission lines Circuit gain calculations E5C04 What are the two families of circles that make up a Smith chart? Resistance and voltage Reactance and voltage Resistance and reactance Voltage and impedance E5C05 What type of chart is shown in Figure E5-1? Smith chart Free-space radiation directivity chart Vertical-space radiation pattern chart Horizontal-space radiation pattern chart E5C06 On the Smith chart shown in Figure E5-1, what is the name for the large outer circle bounding the coordinate portion of the chart? Prime axis Reactance axis Impedance axis Polar axis E5C07 On the Smith chart shown in Figure E5-1, what is the only straight line shown? The reactance axis The current axis The voltage axis The resistance axis E5C08 What is the process of normalizing with regard to a Smith chart? Reassigning resistance values with regard to the reactance axis Reassigning reactance values with regard to the resistance axis Reassigning impedance values with regard to the prime center Reassigning prime center with regard to the reactance axis E5C09 What is the third family of circles, which are added to a Smith chart during the process of solving problems? Standing-wave ratio circles Antenna-length circles Coaxial-length circles Radiation-pattern circles E5C10 In rectangular coordinates, what is the impedance of a network comprised of a 10-microhenry inductor in series with a 40-ohm resistor at 500 MHz? 40 + j31,400 40 - j31,400 31,400 + j40 31,400 - j40 E5C11 In polar coordinates, what is the impedance of a network comprised of a 100-picofarad capacitor in parallel with a 4,000-ohm resistor at 500 kHz? 2490 ohms, ∠51.5 degrees 4000 ohms, ∠38.5 degrees 2490 ohms, ∠-51.5 degrees 5112 ohms, ∠-38.5 degrees E5C13 What are the curved lines on a Smith chart? Portions of current circles Portions of voltage circles Portions of resistance circles Portions of reactance circles E5C14 How are the wavelength scales on a Smith chart calibrated? In portions of transmission line electrical frequency In portions of transmission line electrical wavelength In portions of antenna electrical wavelength In portions of antenna electrical frequency E5D01 What is the phase angle between the voltage across and the current through a series R-L-C circuit if XC is 25 ohms, R is 100 ohms, and XL is 100 ohms? 36.9 degrees with the voltage leading the current 53.1 degrees with the voltage lagging the current 36.9 degrees with the voltage lagging the current 53.1 degrees with the voltage leading the current E5D02 What is the phase angle between the voltage across and the current through a series R-L-C circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms? 68.2 degrees with the voltage leading the current 14.0 degrees with the voltage leading the current 14.0 degrees with the voltage lagging the current 68.2 degrees with the voltage lagging the current E5D03 What is the phase angle between the voltage across and the current through a series R-L-C circuit if XC is 50 ohms, R is 100 ohms, and XL is 25 ohms? 76 degrees with the voltage lagging the current 14 degrees with the voltage leading the current 76 degrees with the voltage leading the current 14 degrees with the voltage lagging the current E5D04 What is the phase angle between the voltage across and the current through a series R-L-C circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms? 14 degrees with the voltage lagging the current 14 degrees with the voltage leading the current 76 degrees with the voltage leading the current 76 degrees with the voltage lagging the current E5D05 What is the phase angle between the voltage across and the current through a series R-L-C circuit if XC is 50 ohms, R is 100 ohms, and XL is 75 ohms? 76 degrees with the voltage leading the current 76 degrees with the voltage lagging the current 14 degrees with the voltage lagging the current 14 degrees with the voltage leading the current E5D06 What is the relationship between the current through and the voltage across a capacitor? Voltage and current are in phase Voltage and current are 180 degrees out of phase Voltage leads current by 90 degrees Current leads voltage by 90 degrees E5D07 What is the relationship between the current through an inductor and the voltage across an inductor? Voltage leads current by 90 degrees Current leads voltage by 90 degrees Voltage and current are 180 degrees out of phase Voltage and current are in phase E5D08 What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms? 14 degrees with the voltage lagging the current 14 degrees with the voltage leading the current 76 degrees with the voltage lagging the current 76 degrees with the voltage leading the current E5D09 What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 75 ohms, R is 100 ohms, and XL is 100 ohms? 76 degrees with the voltage leading the current 14 degrees with the voltage leading the current 14 degrees with the voltage lagging the current 76 degrees with the voltage lagging the current E5D10 What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 75 ohms, R is 100 ohms, and XL is 50 ohms? 76 degrees with the voltage lagging the current 14 degrees with the voltage leading the current 14 degrees with the voltage lagging the current 76 degrees with the voltage leading the current E5D11 What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 250 ohms, R is 1 kilohm, and XL is 500 ohms? 81.47 degrees with the voltage lagging the current 81.47 degrees with the voltage leading the current 14.04 degrees with the voltage lagging the current 14.04 degrees with the voltage leading the current E5E01 In polar coordinates, what is the impedance of a network comprised of a 100-ohm-reactance inductor in series with a 100-ohm resistor? 121 ohms, ∠35 degrees 141 ohms, ∠45 degrees 161 ohms, ∠55 degrees 181 ohms, ∠65 degrees E5E02 In polar coordinates, what is the impedance of a network comprised of a 100-ohm-reactance inductor, a 100-ohm-reactance capacitor, and a 100-ohm resistor all connected in series? 100 ohms, ∠90 degrees 10 ohms, ∠0 degrees 10 ohms, ∠100 degrees 100 ohms, ∠0 degrees E5E03 In polar coordinates, what is the impedance of a network comprised of a 300-ohm-reactance capacitor, a 600-ohm-reactance inductor, and a 400-ohm resistor, all connected in series? 500 ohms, ∠37 degrees 400 ohms, ∠27 degrees 300 ohms, ∠17 degrees 200 ohms, ∠10 degrees E5E04 In polar coordinates, what is the impedance of a network comprised of a 400-ohm-reactance capacitor in series with a 300-ohm resistor? 240 ohms, ∠36.9 degrees 240 ohms, ∠-36.9 degrees 500 ohms, ∠53.1 degrees 500 ohms, ∠-53.1 degrees E5E05 In polar coordinates, what is the impedance of a network comprised of a 400-ohm-reactance inductor in parallel with a 300-ohm resistor? 240 ohms, ∠36.9 degrees 240 ohms, ∠-36.9 degrees 500 ohms, ∠53.1 degrees 500 ohms, ∠-53.1 degrees E5E06 In polar coordinates, what is the impedance of a network comprised of a 100-ohm-reactance capacitor in series with a 100-ohm resistor? 121 ohms, ∠-25 degrees 191 ohms, ∠-85 degrees 161 ohms, ∠-65 degrees 141 ohms, ∠-45 degrees E5E07 In polar coordinates, what is the impedance of a network comprised of a 100-ohm-reactance capacitor in parallel with a 100-ohm resistor? 31 ohms, ∠-15 degrees 51 ohms, ∠-25 degrees 71 ohms, ∠-45 degrees 91 ohms, ∠-65 degrees E5E08 In polar coordinates, what is the impedance of a network comprised of a 300-ohm-reactance inductor in series with a 400-ohm resistor? 400 ohms, ∠27 degrees 500 ohms, ∠37 degrees 500 ohms, ∠47 degrees 700 ohms, ∠57 degrees E5E09 When using rectangular coordinates to graph the impedance of a circuit, what does the horizontal axis represent? The voltage or current associated with the resistive component The voltage or current associated with the reactive component The sum of the reactive and resistive components The difference between the resistive and reactive components E5E10 When using rectangular coordinates to graph the impedance of a circuit, what does the vertical axis represent? The voltage or current associated with the resistive component The voltage or current associated with the reactive component The sum of the reactive and resistive components The difference between the resistive and reactive components E5E11 What do the two numbers represent that are used to define a point on a graph using rectangular coordinates? The horizontal and inverted axes The vertical and inverted axes The coordinate values along the horizontal and vertical axes The phase angle with respect to its prime center E5E12 If you plot the impedance of a circuit using the rectangular coordinate system and find the impedance point falls on the right side of the graph on the horizontal line, what do you know about the circuit? It has to be a direct current circuit It contains resistance and capacitive reactance It contains resistance and inductive reactance It is equivalent to a pure resistance E5E13 Why would you plot the impedance of a circuit using the polar coordinate system? To display the data on an XY chart To give a visual representation of the phase angle To graphically represent the DC component To show the reactance which is present E5E14 What coordinate system can be used to display the resistive, inductive, and/or capacitive reactance components of an impedance? Maidenhead grid National Bureau of Standards Faraday Rectangular E5E15 What coordinate system can be used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance? Maidenhead grid National Bureau of Standards Faraday Polar E5E16 In polar coordinates, what is the impedance of a circuit of 100 -j100 ohms impedance? 141 ohms, ∠-45 degrees 100 ohms, ∠45 degrees 100 ohms, ∠-45 degrees 141 ohms, ∠45 degrees E5E17 In polar coordinates, what is the impedance of a circuit that has an admittance of 7.09 millisiemens at 45 degrees? 5.03 x 10(-5) ohms, ∠45 degrees 141 ohms, ∠-45 degrees 19,900 ohms, ∠-45 degrees 141 ohms, ∠45 degrees E5E18 In rectangular coordinates, what is the impedance of a circuit that has an admittance of 5 millisiemens at -30 degrees? 173 - j100 ohms 200 + j100 ohms 173 + j100 ohms 200 - j100 ohms E5E19 In rectangular coordinates, what is the admittance of a circuit that has an impedance of 240 ohms at 36.9 degrees? 3.33 x 10(-3) - j2.50 x 10(-3) siemens 3.33 x 10(-3) + j2.50 x 10(-3) siemens 192 + j144 siemens 3.33 - j2.50 siemens E5E20 In polar coordinates, what is the impedance of a series circuit consisting of a resistance of 4 ohms, an inductive reactance of 4 ohms, and a capacitive reactance of 1 ohm? 6.4 ohms, ∠53 degrees 5 ohms, ∠37 degrees 5 ohms, ∠45 degrees 10 ohms, ∠-51 degrees E5E21 Which point on Figure E5-2 best represents that impedance of a series circuit consisting of a 400 ohm resistor and a 38 picofarad capacitor at 14 MHz? Point 2 Point 4 Point 5 Point 6 E5E22 Which point in Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and an 18 microhenry inductor at 3.505 MHZ? Point 1 Point 3 Point 7 Point 8 E5E23 Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and a 19 picofarad capacitor at 21.200 MHz? Point 1 Point 3 Point 7 Point 8 E5F01 What is the result of skin effect? As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface Thermal effects on the surface of the conductor increase the impedance Thermal effects on the surface of the conductor decrease the impedance E5F02 What effect causes most of an RF current to flow along the surface of a conductor? Layer effect Seeburg effect Skin effect Resonance effect E5F03 Where does almost all RF current flow in a conductor? Along the surface of the conductor In the center of the conductor In a magnetic field around the conductor In a magnetic field in the center of the conductor E5F04 Why does most of an RF current flow near the surface of a conductor? Because a conductor has AC resistance due to self-inductance Because the RF resistance of a conductor is much less than the DC resistance Because of the heating of the conductor's interior Because of skin effect E5F05 Why is the resistance of a conductor different for RF currents than for direct currents? Because the insulation conducts current at high frequencies Because of the Heisenburg Effect Because of skin effect Because conductors are non-linear devices E5F06 What device is used to store electrical energy in an electrostatic field? A battery A transformer A capacitor An inductor E5F07 What unit measures electrical energy stored in an electrostatic field? Coulomb Joule Watt Volt E5F08 What is a magnetic field? Current through the space around a permanent magnet The space through which a magnetic force acts The space between the plates of a charged capacitor, through which a magnetic force acts The force that drives current through a resistor E5F09 In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow? In the same direction as the current In a direction opposite to the current In all directions; omnidirectional In a direction determined by the left-hand rule E5F10 What determines the strength of a magnetic field around a conductor? The resistance divided by the current The ratio of the current to the resistance The diameter of the conductor The amount of current E5F11 What is the term for energy that is stored in an electromagnetic or electrostatic field? Amperes-joules Potential energy Joules-coulombs Kinetic energy E5G01 What is the Q of a parallel R-L-C circuit if the resonant frequency is 14.128 MHz, L is 2.7 microhenrys and R is 18 kilohms? 75.1 7.51 71.5 0.013 E5G02 What is the Q of a parallel R-L-C circuit if the resonant frequency is 4.468 MHz, L is 47 microhenrys and R is 180 ohms? 0.00735 7.35 0.136 13.3 E5G03 What is the Q of a parallel R-L-C circuit if the resonant frequency is 7.125 MHz, L is 8.2 microhenrys and R is 1 kilohm? 36.8 0.273 0.368 2.72 E5G04 What is the Q of a parallel R-L-C circuit if the resonant frequency is 7.125 MHz, L is 12.6 microhenrys and R is 22 kilohms? 22.1 39 25.6 0.0256 E5G05 What is the Q of a parallel R-L-C circuit if the resonant frequency is 3.625 MHz, L is 42 microhenrys and R is 220 ohms? 23 0.00435 4.35 0.23 E5G06 Why is a resistor often included in a parallel resonant circuit? To increase the Q and decrease the skin effect To decrease the Q and increase the resonant frequency To decrease the Q and increase the bandwidth To increase the Q and decrease the bandwidth E5G07 What is the term for an out-of-phase, nonproductive power associated with inductors and capacitors? Effective power True power Peak envelope power Reactive power E5G08 In a circuit that has both inductors and capacitors, what happens to reactive power? It is dissipated as heat in the circuit It goes back and forth between magnetic and electric fields, but is not dissipated It is dissipated as kinetic energy in the circuit It is dissipated in the formation of inductive and capacitive fields E5G09 In a circuit where the AC voltage and current are out of phase, how can the true power be determined? By multiplying the apparent power times the power factor By subtracting the apparent power from the power factor By dividing the apparent power by the power factor By multiplying the RMS voltage times the RMS current E5G10 What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current? 1.414 0.866 0.5 1.73 E5G11 How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100-V AC at 4 amperes? 400 watts 80 watts 2000 watts 50 watts E5G12 Why would the power used in a circuit be less than the product of the magnitudes of the AC voltage and current? Because there is a phase angle greater than zero between the current and voltage Because there are only resistances in the circuit Because there are no reactances in the circuit Because there is a phase angle equal to zero between the current and voltage E5G13 What is the Q of a parallel RLC circuit if the resonant frequency is 14.128 MHz, L is 4.7 microhenrys and R is 18 kilohms? 4.31 43.1 13.3 0.023 E5G14 What is the Q of a parallel RLC circuit if the resonant frequency is 14.225 MHz, L is 3.5 microhenrys and R is 10 kilohms? 7.35 0.0319 71.5 31.9 E5G15 What is the Q of a parallel RLC circuit if the resonant frequency is 7.125 MHz, L is 10.1 microhenrys and R is 100 ohms? 0.221 4.52 0.00452 22.1 E5G16 What is the Q of a parallel RLC circuit if the resonant frequency is 3.625 MHz, L is 3 microhenrys and R is 2.2 kilohms? 0.031 32.2 31.1 25.6 E5H01 What is the effective radiated power of a repeater station with 50 watts transmitter power output, 4-dB feed line loss, 2-dB duplexer loss, 1-dB circulator loss and 6-dBd antenna gain? 199 watts 39.7 watts 45 watts 62.9 watts E5H02 What is the effective radiated power of a repeater station with 50 watts transmitter power output, 5-dB feed line loss, 3-dB duplexer loss, 1-dB circulator loss and 7-dBd antenna gain? 79.2 watts 315 watts 31.5 watts 40.5 watts E5H03 What is the effective radiated power of a station with 75 watts transmitter power output, 4-dB feed line loss and 10-dBd antenna gain? 600 watts 75 watts 150 watts 299 watts E5H04 What is the effective radiated power of a repeater station with 75 watts transmitter power output, 5-dB feed line loss, 3-dB duplexer loss, 1-dB circulator loss and 6-dBd antenna gain? 37.6 watts 237 watts 150 watts 23.7 watts E5H05 What is the effective radiated power of a station with 100 watts transmitter power output, 1-dB feed line loss and 6-dBd antenna gain? 350 watts 500 watts 20 watts 316 watts E5H06 What is the effective radiated power of a repeater station with 100 watts transmitter power output, 5-dB feed line loss, 3-dB duplexer loss, 1-dB circulator loss and 10-dBd antenna gain? 794 watts 126 watts 79.4 watts 1260 watts E5H07 What is the effective radiated power of a repeater station with 120 watts transmitter power output, 5-dB feed line loss, 3-dB duplexer loss, 1-dB circulator loss and 6-dBd antenna gain? 601 watts 240 watts 60 watts 79 watts E5H08 What is the effective radiated power of a repeater station with 150 watts transmitter power output, 2-dB feed line loss, 2.2-dB duplexer loss and 7-dBd antenna gain? 1977 watts 78.7 watts 420 watts 286 watts E5H09 What is the effective radiated power of a repeater station with 200 watts transmitter power output, 4-dB feed line loss, 3.2-dB duplexer loss, 0.8-dB circulator loss and 10-dBd antenna gain? 317 watts 2000 watts 126 watts 300 watts E5H10 What is the effective radiated power of a repeater station with 200 watts transmitter power output, 2-dB feed line loss, 2.8-dB duplexer loss, 1.2-dB circulator loss and 7-dBd antenna gain? 159 watts 252 watts 632 watts 63.2 watts E5H11 What term describes station output (including the transmitter, antenna and everything in between), when considering transmitter power and system gains and losses? Power factor Half-power bandwidth Effective radiated power Apparent power E5H12 What is reactive power? Wattless, nonproductive power Power consumed in wire resistance in an inductor Power lost because of capacitor leakage Power consumed in circuit Q E5H13 What is the power factor of an RL circuit having a 45 degree phase angle between the voltage and the current? 0.866 1.0 0.5 0.707 E5H14 What is the power factor of an RL circuit having a 30 degree phase angle between the voltage and the current? 1.73 0.5 0.866 0.577 E5H15 How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200V AC at 5 amperes? 200 watts 1000 watts 1600 watts 600 watts E5H16 How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500 watts? 704 W 355 W 252 W 1.42 mW E5I01 What is photoconductivity? The conversion of photon energy to electromotive energy The increased conductivity of an illuminated semiconductor junction The conversion of electromotive energy to photon energy The decreased conductivity of an illuminated semiconductor junction E5I02 What happens to the conductivity of a photoconductive material when light shines on it? It increases It decreases It stays the same It becomes unstable E5I03 What happens to the resistance of a photoconductive material when light shines on it? It increases It becomes unstable It stays the same It decreases E5I04 What happens to the conductivity of a semiconductor junction when light shines on it? It stays the same It becomes unstable It increases It decreases E5I05 What is an optocoupler? A resistor and a capacitor A frequency modulated helium-neon laser An amplitude modulated helium-neon laser An LED and a phototransistor E5I06 What is an optoisolator? An LED and a phototransistor A P-N junction that develops an excess positive charge when exposed to light An LED and a capacitor An LED and a solar cell E5I07 What is an optical shaft encoder? An array of neon or LED indicators whose light transmission path is controlled by a rotating wheel An array of optocouplers whose light transmission path is controlled by a rotating wheel An array of neon or LED indicators mounted on a rotating wheel in a coded pattern An array of optocouplers mounted on a rotating wheel in a coded pattern E5I08 What characteristic of a crystalline solid will photoconductivity change? The capacitance The inductance The specific gravity The resistance E5I09 Which material will exhibit the greatest photoconductive effect when visible light shines on it? Potassium nitrate Lead sulfide Cadmium sulfide Sodium chloride E5I10 Which material will exhibit the greatest photoconductive effect when infrared light shines on it? Potassium nitrate Lead sulfide Cadmium sulfide Sodium chloride E5I11 Which material is affected the most by photoconductivity? A crystalline semiconductor An ordinary metal A heavy metal A liquid semiconductor E5I12 What characteristic of optoisolators is often used in power supplies? They have low impedance between the light source and the phototransistor They have very high impedance between the light source and the phototransistor They have low impedance between the light source and the LED They have very high impedance between the light source and the LED E5I13 What characteristic of optoisolators makes them suitable for use with a triac to form the solid-state equivalent of a mechanical relay for a 120 V AC household circuit? Optoisolators provide a low impedance link between a control circuit and a power circuit Optoisolators provide impedance matching between the control circuit and power circuit Optoisolators provide a very high degree of electrical isolation between a control circuit and a power circuit Optoisolators eliminate (isolate) the effects of reflected light in the control circuit |
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