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Amateur Radio Question PoolsNew! View the differences between the 2008 Extra question pool and the previous pool. Canadian Advanced Qualification Question PoolPrev 1 2 3 4 5 6 7 NextA-001-01-01 What is the meaning of the term "time constant" in an RL circuit? The time required for the current in the circuit to build up to 36.8% of the maximum value The time required for the voltage in the circuit to build up to 63.2% of the maximum value The time required for the voltage in the circuit to build up to 36.8% of the maximum value The time required for the current in the circuit to build up to 63.2% of the maximum value A-001-01-02 What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the supply voltage? One time constant A time factor of one One exponential period A-001-01-03 What is the term for the time required for the current in an RL circuit to build up to 63.2% of the maximum value? An exponential period of one A time factor of one One exponential rate A-001-01-04 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? An exponential discharge of one One time constant One discharge period A-001-01-05 What is meant by "back EMF"? A voltage that opposes the applied EMF An opposing EMF equal to R times C percent of the applied EMF A current equal to the applied EMF A-001-01-06 After two time constants, the capacitor in an RC circuit is charged to what percentage of the supply voltage? 86.5% 95% 36.8% A-001-01-07 After two time constants, the capacitor in an RC circuit is discharged to what percentage of the starting voltage? 36.8% 86.5% 63.2% A-001-01-08 What is the time constant of a circuit having a 100 microfarad capacitor in series with a 470 kilohm resistor? 470 seconds 0.47 seconds 47 seconds A-001-01-09 What is the time constant of a circuit having a 470 microfarad capacitor in series with a 470 kilohm resistor? 47 000 seconds 221 seconds 470 seconds A-001-01-10 What is the time constant of a circuit having a 220 microfarad capacitor in series with a 470 kilohm resistor? 470 seconds 103 seconds 220 seconds A-001-02-01 What is the result of skin effect? 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 impedance Thermal effects on the surface of the conductor decrease impedance A-001-02-02 What effect causes most of an RF current to flow along the surface of a conductor? Resonance effect Skin effect Layer effect A-001-02-03 Where does almost all RF current flow in a conductor? In a magnetic field around the conductor Along the surface of the conductor In the centre of the conductor A-001-02-04 Why does most of an RF current flow within a very thin layer under the conductor's surface? Because of skin effect Because a conductor has AC resistance due to self- inductance Because of heating of the conductor's interior A-001-02-05 Why is the resistance of a conductor different for RF currents than for direct currents? Because of the Hertzberg effect Because conductors are non- linear devices Because the insulation conducts current at high frequencies A-001-02-06 What unit measures the capacity to store electrical energy in an electrostatic field? Watt Volt Farad A-001-02-07 What is an electromagnetic field? The force that drives current through a conductor The current between the plates of a charged capacitor The space around a conductor, through which a magnetic force acts A-001-02-08 In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow? In all directions In the same direction as the current In the direct opposite to the current A-001-02-09 What is the term for energy that is stored in an electromagnetic or electrostatic field? Kinetic energy Ampere-joules Joule-coulombs A-001-02-10 What is an electrostatic field? The space around a conductor, through which a magnetic force acts Current through the space around a permanent magnet The force that drives current through a conductor A-001-02-11 What unit measures the capacity to store electrical energy in an electromagnetic field? Farad Watt Henry A-001-03-01 What is the resonant frequency of a series R-L-C circuit if R is 47 ohms, L is 50 microhenrys and C is 40 picofarads? 3.56 MHz 7.96 MHz 79.6 MHz A-001-03-02 What is the resonant frequency of a series R-L-C circuit, if R is 47 ohms, L is 40 microhenrys and C is 200 picofarads? 1.99 MHz 1.78 kHz 1.78 MHz A-001-03-03 What is the resonant frequency of a series R-L-C circuit, if R is 47 ohms, L is 50 microhenrys and C is 10 picofarads? 3.18 MHz 3.18 kHz 7.12 MHz A-001-03-04 What is the resonant frequency of a series R-L-C circuit, if R is 47 ohms, L is 25 microhenrys and C is 10 picofarads? 10.1 kHz 63.7 kHz 10.1 MHz A-001-03-05 What is the resonant frequency of a series R-L-C circuit, if R is 47 ohms, L is 3 microhenrys and C is 40 picofarads? 14.5 MHz 13.1 kHz 14.5 kHz A-001-03-06 What is the resonant frequency of a series R-L-C circuit, if R is 47 ohms, L is 4 microhenrys and C is 20 picofarads? 17.8 MHz 19.9 kHz 17.8 kHz A-001-03-07 What is the resonant frequency of a series R-L-C circuit, if R is 47 ohms, L is 8 microhenrys and C is 7 picofarads? 21.3 MHz 2.84 MHz 2.13 MHz A-001-03-08 What is the resonant frequency of a series R-L-C circuit, if R is 47 ohms, L is 3 microhenrys and C is 15 picofarads? 23.7 MHz 35.4 kHz 23.7 kHz A-001-03-09 What is the resonant frequency of a series R-L-C circuit, if R is 47 ohms, L is 4 microhenrys and C is 8 picofarads? 28.1 MHz 49.7 kHz 28.1 kHz A-001-03-10 What is the resonant frequency of a series R-L-C circuit, if R is 47 ohms, L is 1 microhenry and C is 9 picofarads? 5.31 MHz 17.7 MHz 1.77 MHz A-001-03-11 What is the value of capacitance (C) in a series R- L-C circuit, if the circuit resonant frequency is 14.25 MHz and L is 2.84 microhenrys? 44 microfarads 44 picofarads 2.2 picofarads A-001-04-01 What is the resonant frequency of a parallel R-L-C circuit if R is 4.7 kilohms, L is 1 microhenry and C is 10 picofarads? 50.3 MHz 50.3 kHz 15.9 MHz A-001-04-02 What is the resonant frequency of a parallel R-L-C circuit if R is 4.7 kilohms, L is 2 microhenrys and C is 15 picofarads? 29.1 kHz 5.31 MHz 5.31 kHz A-001-04-03 What is the resonant frequency of a parallel R-L-C circuit if R is 4.7 kilohms, L is 5 microhenrys and C is 9 picofarads? 3.54 MHz 3.54 kHz 23.7 MHz A-001-04-04 What is the resonant frequency of a parallel R-L-C circuit if R is 4.7 kilohms, L is 2 microhenrys and C is 30 picofarads? 20.5 MHz 2.65 kHz 20.5 kHz A-001-04-05 What is the resonant frequency of a parallel R-L-C circuit if R is 4.7 kilohms, L is 15 microhenrys and C is 5 picofarads? 2.12 MHz 18.4 MHz 18.4 kHz A-001-04-06 What is the resonant frequency of a parallel R-L-C circuit if R is 4.7 kilohms, L is 3 microhenrys and C is 40 picofarads? 1.33 MHz 14.5 MHz 14.5 kHz A-001-04-07 What is the resonant frequency of a parallel R-L-C circuit if R is 4.7 kilohms, L is 40 microhenrys and C is 6 picofarads? . 10.3 MHz 6.63 kHz 10.3 kHz A-001-04-08 What is the resonant frequency of a parallel R-L-C circuit if R is 4.7 kilohms, L is 10 microhenrys and C is 50 picofarads? 7.12 kHz 3.18 MHz 3.18 kHz A-001-04-09 What is the resonant frequency of a parallel R-L-C circuit if R is 4.7 kilohms, L is 200 microhenrys and C is 10 picofarads? 7.96 MHz 7.96 kHz 3.56 MHz A-001-04-10 What is the resonant frequency of a parallel R-L-C circuit if R is 4.7 kilohms, L is 90 microhenrys and C is 100 picofarads? 1.77 MHz 1.68 MHz 1.68 kHz A-001-04-11 What is the value of inductance (L) in a parallel R-L-C circuit, if the resonant frequency is 14.25 MHz and C is 44 picofarads? 3.9 millihenrys 0.353 microhenry 2.8 microhenrys A-001-05-01 What is the Q of a parallel R- L-C circuit, if it is resonant at 14.128 MHz, L is 2.7 microhenrys and R is 18 kilohms? 0.013 71.5 75.1 A-001-05-02 What is the Q of a parallel R- L-C circuit, if it is resonant at 14.128 MHz, L is 4.7 microhenrys and R is 18 kilohms? 43.1 0.023 4.31 A-001-05-03 What is the Q of a parallel R- L-C circuit, if it is resonant at 4.468 MHz, L is 47 microhenrys and R is 180 ohms? 7.35 0.00735 13.3 A-001-05-04 What is the Q of a parallel R- L-C circuit, if it is resonant at 14.225 MHz, L is 3.5 microhenrys and R is 10 kilohms? 31.9 0.0319 71.5 A-001-05-05 What is the Q of a parallel R- L-C circuit, if it is resonant at 7.125 MHz, L is 8.2 microhenrys and R is 1 kilohm? 36.8 0.368 0.273 A-001-05-06 What is the Q of a parallel R- L-C circuit, if it is resonant at 7.125 MHz, L is 10.1 microhenrys and R is 100 ohms? 0.00452 0.221 4.52 A-001-05-07 What is the Q of a parallel R- L-C circuit, if it is resonant at 7.125 MHz, L is 12.6 microhenrys and R is 22 kilohms? 22.1 0.0256 25.6 A-001-05-08 What is the Q of a parallel R- L-C circuit, if it is resonant at 3.625 MHz, L is 3 microhenrys and R is 2.2 kilohms? 31.1 32.2 0.031 A-001-05-09 What is the Q of a parallel R- L-C circuit, if it is resonant at 3.625 MHz, L is 42 microhenrys and R is 220 ohms? 4.35 0.23 0.00435 A-001-05-10 What is the Q of a parallel R- L-C circuit, if it is resonant at 3.625 MHz, L is 43 microhenrys and R is 1.8 kilohms? 54.3 23 1.84 A-001-05-11 Why is a resistor often included in a parallel resonant circuit? To decrease the Q and increase the resonant frequency To increase the Q and decrease bandwidth To decrease the Q and increase the bandwidth |
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