001 - Advanced Theory Flashcards
A-001-001-001
What is the meaning of the term “time constant” in an RL circuit ?
(a) The time required for the current in the circuit to build up to 36.8% of the maximum value
(b) The time required for the voltage in the circuit to build up to 63.2% of the maximum value
(c) The time required for the current in the circuit to build up to 63.2% of the maximum value
(d) The time required for the voltage in the circuit to build up to 36.8% of the maximum value
A-001-001-001
What is the meaning of the term “time constant” in an RL circuit ?
(c) The time required for the current in the circuit to build up to 63.2% of the maximum value
A-001-001-002
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?
(a) One time constant
(b) An exponential rate of one
(c) A time factor of one
(d) One exponential period
A-001-001-002
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?
(a) One time constant
A-001-001-003
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?
(a) One time constant
(b) An exponential period of one
(c) A time factor of one
(d) One exponential rate
A-001-001-003
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?
(a) One time constant
A-001-001-004
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) A discharge factor of one
(b) One time constant
(c) An exponential discharge of one
(d) One discharge period
A-001-001-004
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?
(b) One time constant
A-001-001-005
What is meant by “back EMF”?
(a) A current that opposes the applied EMF
(b) An opposing EMF equal to R times C percent of the applied EMF
(c) A voltage that opposes the applied EMF
(d) A current equal to the applied EMF
A-001-001-005
What is meant by “back EMF”?
(c) A voltage that opposes the applied EMF
A-001-001-006
After two time constants, the capacitor in an RC circuit is charged to what percentage of the supply voltage?
(a) 63.2%
(b) 95%
(c) 86.5%
(d) 36.8%
A-001-001-006
After two time constants, the capacitor in an RC circuit is charged to what percentage of the supply voltage?
(c) 86.5%
A-001-001-007
After two time constants, the capacitor in an RC circuit is discharged to what percentage of the starting voltage?
(a) 36.8%
(b) 86.5%
(c) 63.2%
(d) 13.5%
A-001-001-007
After two time constants, the capacitor in an RC circuit is discharged to what percentage of the starting voltage?
(d) 13.5%
A-001-001-008
What is the time constant of a circuit having a 100 microfarad capacitor in series with a 470 kilohm resistor?
(a) 4700 seconds
(b) 47 seconds
(c) 470 seconds
(d) 0.47 seconds
A-001-001-008
What is the time constant of a circuit having a 100 microfarad capacitor in series with a 470 kilohm resistor?
(b) 47 seconds
A-001-001-009
What is the time constant of a circuit having a 470 microfarad capacitor in series with a 470 kilohm resistor?
(a) 221 000 seconds
(b) 47 000 seconds
(c) 221 seconds
(d) 470 seconds
A-001-001-009
What is the time constant of a circuit having a 470 microfarad capacitor in series with a 470 kilohm resistor?
(c) 221 seconds
A-001-001-010
What is the time constant of a circuit having a 220 microfarad capacitor in series with a 470 kilohm resistor?
(a) 470 000 seconds
(b) 470 seconds
(c) 220 seconds
(d) 103 seconds
A-001-001-010
What is the time constant of a circuit having a 220 microfarad capacitor in series with a 470 kilohm resistor?
(d) 103 seconds
A-001-002-001
What is the result of skin effect?
(a) As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
(b) Thermal effects on the surface of the conductor increase impedance
(c) As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
(d) Thermal effects on the surface of the conductor decrease impedance
A-001-002-001
What is the result of skin effect?
(c) As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
A-001-002-002
What effect causes most of an RF current to flow along the surface of a conductor?
(a) Piezoelectric effect
(b) Resonance effect
(c) Layer effect
(d) Skin effect
A-001-002-002
What effect causes most of an RF current to flow along the surface of a conductor?
(d) Skin effect
A-001-002-003
Where does almost all RF current flow in a conductor?
(a) In a magnetic field in the centre of the conductor
(b) In a magnetic field around the conductor
(c) Along the surface of the conductor
(d) In the centre of the conductor
A-001-002-003
Where does almost all RF current flow in a conductor?
(c) Along the surface of the conductor
A-001-002-004
Why does most of an RF current flow within a very thin layer under the conductor’s surface?
(a) Because the RF resistance of a conductor is much less than the DC resistance
(b) Because a conductor has AC resistance due to self-inductance
(c) Because of heating of the conductor’s interior
(d) Because of skin effect
A-001-002-004
Why does most of an RF current flow within a very thin layer under the conductor’s surface?
(d) Because of skin effect
A-001-002-005
Why is the resistance of a conductor different for RF currents than for direct currents?
(a) Because of the Hertzberg effect
(b) Because of skin effect
(c) Because conductors are non-linear devices
(d) Because the insulation conducts current at high frequencies
A-001-002-005
Why is the resistance of a conductor different for RF currents than for direct currents?
(b) Because of skin effect
A-001-002-006
What unit measures the ability of a capacitor to store electrical charge?
(a) Coulomb
(b) Watt
(c) Volt
(d) Farad
A-001-002-006
What unit measures the ability of a capacitor to store electrical charge?
(d) Farad
A-001-002-007
A wire has a current passing through it. Surrounding this wire there is:
(a) an electrostatic field
(b) a cloud of electrons
(c) a skin effect that diminishes with distance
(d) an electromagnetic field
A-001-002-007
A wire has a current passing through it. Surrounding this wire there is:
(d) an electromagnetic field
A-001-002-008
In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?
(a) In all directions
(b) In the same direction as the current
(c) In the direct opposite to the current
(d) In the direction determined by the left-hand rule
A-001-002-008
In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?
(d) In the direction determined by the left-hand rule
A-001-002-009
What is the term for energy that is stored in an electromagnetic or electrostatic field?
(a) Kinetic energy
(b) Ampere-joules
(c) Joule-coulombs
(d) Potential energy
A-001-002-009
What is the term for energy that is stored in an electromagnetic or electrostatic field?
(d) Potential energy
A-001-002-010
Between the charged plates of a capacitor there is:
(a) a magnetic field
(b) a cloud of electrons
(c) an electric current
(d) an electrostatic field
A-001-002-010
Between the charged plates of a capacitor there is:
(d) an electrostatic field
A-001-002-011
Energy is stored within an inductor that is carrying a current. The amount of energy depends on this current, but it also depends on a property of the inductor. This property has the following unit:
(a) coulomb
(b) farad
(c) watt
(d) henry
A-001-002-011
Energy is stored within an inductor that is carrying a current. The amount of energy depends on this current, but it also depends on a property of the inductor. This property has the following unit:
(d) henry
