# RIC-8 — Advanced Qualification Question Bank for Amateur Radio Operator Certificate

A-001-01-01 (4)
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 (2)
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?

• An exponential rate of one
• One time constant
• A time factor of one
• One exponential period

A-001-01-03 (1)
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?

• One time constant
• An exponential period of one
• A time factor of one
• One exponential rate

A-001-01-04 (3)
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?

• A discharge factor of one
• An exponential discharge of one
• One time constant
• One discharge period

A-001-01-05 (2)
What is meant by "back EMF"?

• A current that opposes the applied 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 (2)
After two time constants, the capacitor in an RC circuit is charged to what percentage of the supply voltage?

• 63.2%
• 86.5%
• 95%
• 36.8%

A-001-01-07 (1)
After two time constants, the capacitor in an RC circuit is discharged to what percentage of the starting voltage?

• 13.5%
• 36.8%
• 86.5%
• 63.2%

A-001-01-08 (4)
What is the time constant of a circuit having a 100 microfarad capacitor in series with a 470 kilohm resistor?

• 4700 seconds
• 470 seconds
• 0.47 seconds
• 47 seconds

A-001-01-09 (3)
What is the time constant of a circuit having a 470 microfarad capacitor in series with a 470 kilohm resistor?

• 221 000 seconds
• 47 000 seconds
• 221 seconds
• 470 seconds

A-001-01-10 (3)
What is the time constant of a circuit having a 220 microfarad capacitor in series with a 470 kilohm resistor?

• 470 000 seconds
• 470 seconds
• 103 seconds
• 220 seconds
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A-001-02-01 (1)
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 impedance
• Thermal effects on the surface of the conductor decrease impedance

A-001-02-02 (3)
What effect causes most of an RF current to flow along the surface of a conductor?

• Piezoelectric effect
• Resonance effect
• Skin effect
• Layer effect

A-001-02-03 (3)
Where does almost all RF current flow in a conductor?

• In a magnetic field in the centre of the conductor
• In a magnetic field around the conductor
• Along the surface of the conductor
• In the centre of the conductor

A-001-02-04 (2)
Why does most of an RF current flow within a very thin layer under the conductor's surface?

• Becasue the RF resistance of a conductor is much less than the DC resistance
• 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 (1)
Why is the resistance of a conductor different for RF currents than for direct currents?

• Because of skin effect
• Because of the Hertzberg effect
• Because conductors are non-linear devices
• Because the insulation conducts current at high frequencies

A-001-02-06 (4)
What unit measures the capacity to store electrical energy in an electrostatic field?

• Coulomb
• Watt
• Volt

A-001-02-07 (4)
What is an electromagnetic field?

• Current through the space around a permanent magnet
• 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 (1)
In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

• In the direction determined by the lefthand rule
• In all directions
• In the same direction as the current
• In the direct opposite to the current

A-001-02-09 (1)
What is the term for energy that is stored in an electromagnetic or electrostatic field?

• Potential energy
• Kinetic energy
• Ampere-joules
• Joule-coulombs

A-001-02-10 (1)
What is an electrostatic field?

• The current between the plates of a charged capacitor
• 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
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A-001-02-11 (4)
What unit measures the capacity to store electrical energy in an electromagnetic field?

• Coulomb
• Watt
• Henry

A-001-03-01 (2)
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?

• 1.78 MHz
• 3.56 MHz
• 7.96 MHz
• 79.6 MHz

A-001-03-02 (4)
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 kHz
• 1.99 MHz
• 1.78 kHz
• 1.78 MHz

A-001-03-03 (4)
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?

• 7.12 kHz
• 3.18 MHz
• 3.18 kHz
• 7.12 MHz

A-001-03-04 (4)
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?

• 63.7 MHz
• 10.1 kHz
• 63.7 kHz
• 10.1 MHz

A-001-03-05 (2)
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?

• 13.1 MHz
• 14.5 MHz
• 13.1 kHz
• 14.5 kHz

A-001-03-06 (2)
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?

• 19.9 MHz
• 17.8 MHz
• 19.9 kHz
• 17.8 kHz

A-001-03-07 (2)
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?

• 28.4 MHz
• 21.3 MHz
• 2.84 MHz
• 2.13 MHz

A-001-03-08 (2)
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?

• 35.4 MHz
• 23.7 MHz
• 35.4 kHz
• 23.7 kHz

A-001-03-09 (2)
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?

• 49.7 MHz
• 28.1 MHz
• 49.7 kHz
• 28.1 kHz
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A-001-03-10 (1)
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?

• 53.1 MHz
• 5.31 MHz
• 17.7 MHz
• 1.77 MHz

A-001-03-11 (3)
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?

A-001-04-01 (2)
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?

• 15.9 kHz
• 50.3 MHz
• 50.3 kHz
• 15.9 MHz

A-001-04-02 (1)
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 MHz
• 29.1 kHz
• 5.31 MHz
• 5.31 kHz

A-001-04-03 (4)
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?

• 23.7 kHz
• 3.54 MHz
• 3.54 kHz
• 23.7 MHz

A-001-04-04 (2)
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?

• 2.65 MHz
• 20.5 MHz
• 2.65 kHz
• 20.5 kHz

A-001-04-05 (3)
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 kHz
• 2.12 MHz
• 18.4 MHz
• 18.4 kHz

A-001-04-06 (3)
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 kHz
• 1.33 MHz
• 14.5 MHz
• 14.5 kHz

A-001-04-07 (2)
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?

• 6.63 MHz
• 10.3 MHz
• 6.63 kHz
• 10.3 kHz

A-001-04-08 (1)
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 MHz
• 7.12 kHz
• 3.18 MHz
• 3.18 kHz
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A-001-04-09 (4)
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?

• 3.56 kHz
• 7.96 MHz
• 7.96 kHz
• 3.56 MHz

A-001-04-10 (3)
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 kHz
• 1.77 MHz
• 1.68 MHz
• 1.68 kHz

A-001-04-11 (4)
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?

• 253.8 millihenrys
• 3.9 millihenrys
• 0.353 microhenry
• 2.8 microhenrys

A-001-05-01 (4)
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?

• 7.51
• 0.013
• 71.5
• 75.1

A-001-05-02 (2)
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?

• 13.3
• 43.1
• 0.023
• 4.31

A-001-05-03 (1)
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?

• 0.136
• 7.35
• 0.00735
• 13.3

A-001-05-04 (2)
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?

• 7.35
• 31.9
• 0.0319
• 71.5

A-001-05-05 (1)
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?

• 2.73
• 36.8
• 0.368
• 0.273

A-001-05-06 (3)
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?

• 22.1
• 0.00452
• 0.221
• 4.52

A-001-05-07 (1)
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?

• 39
• 22.1
• 0.0256
• 25.6
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A-001-05-08 (3)
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?

• 25.6
• 31.1
• 32.2
• 0.031

A-001-05-09 (3)
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?

• 2.3
• 4.35
• 0.23
• 0.00435

A-001-05-10 (4)
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?

• 0.543
• 54.3
• 23
• 1.84

A-001-05-11 (4)
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 increase the Q and decrease bandwidth
• To decrease the Q and increase the bandwidth