FCC Element 3 Best Exam Questions
With Detailed Solution
3-1A1 The product of the readings of an AC voltmeter and AC ammeter is called: -
CORRECT ANSWER-Apparent power.
3-1A2 What is the basic unit of electrical power? - CORRECT ANSWER-Watt.
3-1A3 What is the term used to express the amount of electrical energy stored in an
electrostatic field? - CORRECT ANSWER-Joules.
3-1A4 What device is used to store electrical energy in an electrostatic field? -
CORRECT ANSWER-. Capacitor.
3-1A5 What formula would determine the inductive reactance of a coil if frequency and
coil inductance are known? - CORRECT ANSWER-XL = 2f L
3-1A6 What is the term for the out-of-phase power associated with inductors and
capacitors? - CORRECT ANSWER-Reactive power.
3-2A1 What determines the strength of the magnetic field around a conductor? -
CORRECT ANSWER-The amount of current.
3-2A2 What will produce a magnetic field? - CORRECT ANSWER-A current flowing
through a conductor.
3-2A3 When induced currents produce expanding magnetic fields around conductors in
a direction that opposes the original magnetic field, this is known as: - CORRECT
ANSWER-Lenz's law.
3-2A4 The opposition to the creation of magnetic lines of force in a magnetic circuit is
known as: - CORRECT ANSWER-Reluctance.
,3-2A5 What is meant by the term "back EMF"? - CORRECT ANSWER-A voltage that
opposes the applied EMF.
3-2A6 Permeability is defined as: - CORRECT ANSWER-The ratio of magnetic flux
density in a substance to the magnetizing force that produces it.
3-3A1 What metal is usually employed as a sacrificial anode for corrosion control
purposes? - CORRECT ANSWER-Zinc bar.
3-3A2 What is the relative dielectric constant for air? - CORRECT ANSWER-1
3-3A3 Which metal object may be least affected by galvanic corrosion when submerged
in seawater? - CORRECT ANSWER-Stainless steel propeller shaft.
3-3A4 Skin effect is the phenomenon where: - CORRECT ANSWER-RF current flows in
a thin layer of the conductor, closer to the surface, as frequency increases.
3-3A5 Corrosion resulting from electric current flow between dissimilar metals is called:
- CORRECT ANSWER-Galvanic corrosion.
3-3A6 Which of these will be most useful for insulation at UHF frequencies? -
CORRECT ANSWER-Mica.
3-4A1 What formula would calculate the total inductance of inductors in series? -
CORRECT ANSWER-LT = L1 + L2
3-4A2 Good conductors with minimum resistance have what type of electrons? -
CORRECT ANSWER-Many free electrons.
3-4A3 Which of the 4 groups of metals listed below are the best low-resistance
conductors? - CORRECT ANSWER-Gold, silver, and copper.
,3-4A4 What is the purpose of a bypass capacitor? - CORRECT ANSWER-It removes
alternating current by providing a low impedance path to ground.
3-4A5 How would you calculate the total capacitance of three capacitors in parallel? -
CORRECT ANSWER-CT = C1 + C2 + C3.
3-4A6 How might you reduce the inductance of an antenna coil? - CORRECT
ANSWER-Reduce the number of turns.
3-5A1 What are the two most commonly-used specifications for a junction diode? -
CORRECT ANSWER-Maximum forward current and PIV (peak inverse voltage).
3-5A2 What limits the maximum forward current in a junction diode? - CORRECT
ANSWER-The junction temperature.
3-5A3 MOSFETs are manufactured with THIS protective device built into their gate to
protect the device from - CORRECT ANSWER-Zener diode.
3-5A4 What are the two basic types of junction field-effect transistors? - CORRECT
ANSWER-N-channel and P-channel.
3-5A5 A common emitter amplifier has: - CORRECT ANSWER-. More voltage gain than
a common collector.
3-5A6 How does the input impedance of a field-effect transistor compare with that of a
bipolar transistor? - CORRECT ANSWER-An FET has high input impedance; a bipolar
transistor has low input impedance.
3-6A1 An AC ammeter indicates: - CORRECT ANSWER-. Effective (RMS) values of
current.
3-6A2 By what factor must the voltage of an AC circuit, as indicated on the scale of an
AC voltmeter, be multiplied to obtain the peak voltage value? - CORRECT ANSWER-.
1.414
, 3-6A3 What is the RMS voltage at a common household electrical power outlet? -
CORRECT ANSWER-117-V AC.
3-6A4 What is the easiest voltage amplitude to measure by viewing a pure sine wave
signal on an oscilloscope? - CORRECT ANSWER-. Peak-to-peak.
3-6A5 By what factor must the voltage measured in an AC circuit, as indicated on the
scale of an AC voltmeter, be multiplied to obtain the average voltage value? -
CORRECT ANSWER-. 0.9
3-6A6 What is the peak voltage at a common household electrical outlet? - CORRECT
ANSWER-. 165.5 volts.
3-7A1 What is a sine wave? - CORRECT ANSWER-. A wave whose amplitude at any
given instant can be represented by the projection of a point on a wheel rotating at a
uniform speed.
3-7A2 How many degrees are there in one complete sine wave cycle? - CORRECT
ANSWER-. 360 degrees.
3-7A3 What type of wave is made up of sine waves of the fundamental frequency and
all the odd harmonics? - CORRECT ANSWER-. Square.
3-7A4 What is the description of a square wave? - CORRECT ANSWER-. A wave that
abruptly changes back and forth between two voltage levels and stays at these levels
for equal amounts of time.
3-7A5 What type of wave is made up of sine waves at the fundamental frequency and
all the harmonics? - CORRECT ANSWER-Sawtooth wave.
3-7A6 What type of wave is characterized by a rise time significantly faster than the fall
time (or vice versa)? - CORRECT ANSWER-Sawtooth wave.
With Detailed Solution
3-1A1 The product of the readings of an AC voltmeter and AC ammeter is called: -
CORRECT ANSWER-Apparent power.
3-1A2 What is the basic unit of electrical power? - CORRECT ANSWER-Watt.
3-1A3 What is the term used to express the amount of electrical energy stored in an
electrostatic field? - CORRECT ANSWER-Joules.
3-1A4 What device is used to store electrical energy in an electrostatic field? -
CORRECT ANSWER-. Capacitor.
3-1A5 What formula would determine the inductive reactance of a coil if frequency and
coil inductance are known? - CORRECT ANSWER-XL = 2f L
3-1A6 What is the term for the out-of-phase power associated with inductors and
capacitors? - CORRECT ANSWER-Reactive power.
3-2A1 What determines the strength of the magnetic field around a conductor? -
CORRECT ANSWER-The amount of current.
3-2A2 What will produce a magnetic field? - CORRECT ANSWER-A current flowing
through a conductor.
3-2A3 When induced currents produce expanding magnetic fields around conductors in
a direction that opposes the original magnetic field, this is known as: - CORRECT
ANSWER-Lenz's law.
3-2A4 The opposition to the creation of magnetic lines of force in a magnetic circuit is
known as: - CORRECT ANSWER-Reluctance.
,3-2A5 What is meant by the term "back EMF"? - CORRECT ANSWER-A voltage that
opposes the applied EMF.
3-2A6 Permeability is defined as: - CORRECT ANSWER-The ratio of magnetic flux
density in a substance to the magnetizing force that produces it.
3-3A1 What metal is usually employed as a sacrificial anode for corrosion control
purposes? - CORRECT ANSWER-Zinc bar.
3-3A2 What is the relative dielectric constant for air? - CORRECT ANSWER-1
3-3A3 Which metal object may be least affected by galvanic corrosion when submerged
in seawater? - CORRECT ANSWER-Stainless steel propeller shaft.
3-3A4 Skin effect is the phenomenon where: - CORRECT ANSWER-RF current flows in
a thin layer of the conductor, closer to the surface, as frequency increases.
3-3A5 Corrosion resulting from electric current flow between dissimilar metals is called:
- CORRECT ANSWER-Galvanic corrosion.
3-3A6 Which of these will be most useful for insulation at UHF frequencies? -
CORRECT ANSWER-Mica.
3-4A1 What formula would calculate the total inductance of inductors in series? -
CORRECT ANSWER-LT = L1 + L2
3-4A2 Good conductors with minimum resistance have what type of electrons? -
CORRECT ANSWER-Many free electrons.
3-4A3 Which of the 4 groups of metals listed below are the best low-resistance
conductors? - CORRECT ANSWER-Gold, silver, and copper.
,3-4A4 What is the purpose of a bypass capacitor? - CORRECT ANSWER-It removes
alternating current by providing a low impedance path to ground.
3-4A5 How would you calculate the total capacitance of three capacitors in parallel? -
CORRECT ANSWER-CT = C1 + C2 + C3.
3-4A6 How might you reduce the inductance of an antenna coil? - CORRECT
ANSWER-Reduce the number of turns.
3-5A1 What are the two most commonly-used specifications for a junction diode? -
CORRECT ANSWER-Maximum forward current and PIV (peak inverse voltage).
3-5A2 What limits the maximum forward current in a junction diode? - CORRECT
ANSWER-The junction temperature.
3-5A3 MOSFETs are manufactured with THIS protective device built into their gate to
protect the device from - CORRECT ANSWER-Zener diode.
3-5A4 What are the two basic types of junction field-effect transistors? - CORRECT
ANSWER-N-channel and P-channel.
3-5A5 A common emitter amplifier has: - CORRECT ANSWER-. More voltage gain than
a common collector.
3-5A6 How does the input impedance of a field-effect transistor compare with that of a
bipolar transistor? - CORRECT ANSWER-An FET has high input impedance; a bipolar
transistor has low input impedance.
3-6A1 An AC ammeter indicates: - CORRECT ANSWER-. Effective (RMS) values of
current.
3-6A2 By what factor must the voltage of an AC circuit, as indicated on the scale of an
AC voltmeter, be multiplied to obtain the peak voltage value? - CORRECT ANSWER-.
1.414
, 3-6A3 What is the RMS voltage at a common household electrical power outlet? -
CORRECT ANSWER-117-V AC.
3-6A4 What is the easiest voltage amplitude to measure by viewing a pure sine wave
signal on an oscilloscope? - CORRECT ANSWER-. Peak-to-peak.
3-6A5 By what factor must the voltage measured in an AC circuit, as indicated on the
scale of an AC voltmeter, be multiplied to obtain the average voltage value? -
CORRECT ANSWER-. 0.9
3-6A6 What is the peak voltage at a common household electrical outlet? - CORRECT
ANSWER-. 165.5 volts.
3-7A1 What is a sine wave? - CORRECT ANSWER-. A wave whose amplitude at any
given instant can be represented by the projection of a point on a wheel rotating at a
uniform speed.
3-7A2 How many degrees are there in one complete sine wave cycle? - CORRECT
ANSWER-. 360 degrees.
3-7A3 What type of wave is made up of sine waves of the fundamental frequency and
all the odd harmonics? - CORRECT ANSWER-. Square.
3-7A4 What is the description of a square wave? - CORRECT ANSWER-. A wave that
abruptly changes back and forth between two voltage levels and stays at these levels
for equal amounts of time.
3-7A5 What type of wave is made up of sine waves at the fundamental frequency and
all the harmonics? - CORRECT ANSWER-Sawtooth wave.
3-7A6 What type of wave is characterized by a rise time significantly faster than the fall
time (or vice versa)? - CORRECT ANSWER-Sawtooth wave.
