T5 - Electrical principles [4 Exam Questions - 4 Groups] Flashcards
Electrical current is measured in which of the following units?
A. Volts
B. Watts
C. Ohms
D. Amperes
D. Amperes
Electrical power is measured in which of the following units?
A. Volts
B. Watts
C. Ohms
D. Amperes
B. Watts
What is the name for the flow of electrons in an electric circuit?
A. Voltage
B. Resistance
C. Capacitance
D. Current
D. Current
What is the name for a current that flows only in one direction?
A. Alternating current
B. Direct current
C. Normal current
D. Smooth current
B. Direct current
What is the electrical term for the electromotive force (EMF) that causes electron flow?
A. Voltage
B. Ampere-hours
C. Capacitance
D. Inductance
A. Voltage
How much voltage does a mobile transceiver usually require?
A. About 12 volts
B. About 30 volts
C. About 120 volts
D. About 240 volts
A. About 12 volts
Which of the following is a good electrical conductor?
A. Glass
B. Wood
C. Copper
D. Rubber
C. Copper
Which of the following is a good electrical insulator?
A. Copper
B. Glass
C. Aluminum
D. Mercury
B. Glass
What is the name for a current that reverses direction on a regular basis?
A. Alternating current
B. Direct current
C. Circular current
D. Vertical current
A. Alternating current
Which term describes the rate at which electrical energy is used?
A. Resistance
B. Current
C. Power
D. Voltage
C. Power
What is the basic unit of electromotive force?
A. The volt
B. The watt
C. The ampere
D. The ohm
A. The volt
What term describes the number of times per second that an alternating current reverses direction?
A. Pulse rate
B. Speed
C. Wavelength
D. Frequency
D. Frequency
How many milliamperes is 1.5 amperes?
A. 15 milliamperes
B. 150 milliamperes
C. 1,500 milliamperes
D. 15,000 milliamperes
C. 1,500 milliamperes
What is another way to specify a radio signal frequency of 1,500,000 hertz?
A. 1500 kHz
B. 1500 MHz
C. 15 GHz
D. 150 kHz
A. 1500 kHz
How many volts are equal to one kilovolt?
A. One one-thousandth of a volt
B. One hundred volts
C. One thousand volts
D. One million volts
C. One thousand volts
How many volts are equal to one microvolt?
A. One one-millionth of a volt
B. One million volts
C. One thousand kilovolts
D. One one-thousandth of a volt
A. One one-millionth of a volt
Which of the following is equivalent to 500 milliwatts?
A. 0.02 watts
B. 0.5 watts
C. 5 watts
D. 50 watts
B. 0.5 watts
If an ammeter calibrated in amperes is used to measure a 3000-milliampere current, what reading would it show?
A. 0.003 amperes
B. 0.3 amperes
C. 3 amperes
D. 3,000,000 amperes
C. 3 amperes
If a frequency readout calibrated in megahertz shows a reading of 3.525 MHz, what would it show if it were calibrated in kilohertz?
A. 0.003525 kHz
B. 35.25 kHz
C. 3525 kHz
D. 3,525,000 kHz
C. 3525 kHz
How many microfarads are 1,000,000 picofarads?
A. 0.001 microfarads
B. 1 microfarad
C. 1000 microfarads
D. 1,000,000,000 microfarads
B. 1 microfarad
What is the approximate amount of change, measured in decibels (dB), of a power increase from 5 watts to 10 watts?
A. 2 dB
B. 3 dB
C. 5 dB
D. 10 dB
B. 3 dB
What is the approximate amount of change, measured in decibels (dB), of a power decrease from 12 watts to 3 watts?
A. -1 dB
B. -3 dB
C. -6 dB
D. -9 dB
C. -6 dB
What is the approximate amount of change, measured in decibels (dB), of a power increase from 20 watts to 200 watts?
A. 10 dB
B. 12 dB
C. 18 dB
D. 28 dB
A. 10 dB
Which of the following frequencies is equal to 28,400 kHz?
A. 28.400 MHz
B. 2.800 MHz
C. 284.00 MHz
D. 28.400 kHz
A. 28.400 MHz
If a frequency readout shows a reading of 2425 MHz, what frequency is that in GHz?
A. 0.002425 GHZ
B. 24.25 GHz
C. 2.425 GHz
D. 2425 GHz
C. 2.425 GHz
What is the ability to store energy in an electric field called?
A. Inductance
B. Resistance
C. Tolerance
D. Capacitance
D. Capacitance
What is the basic unit of capacitance?
A. The farad
B. The ohm
C. The volt
D. The henry
A. The farad
What is the ability to store energy in a magnetic field called?
A. Admittance
B. Capacitance
C. Resistance
D. Inductance
D. Inductance
What is the basic unit of inductance?
A. The coulomb
B. The farad
C. The henry
D. The ohm
C. The henry
What is the unit of frequency?
A. Hertz
B. Henry
C. Farad
D. Tesla
A. Hertz
What does the abbreviation ‘‘R’’ refer to?
A. Radio frequency signals of all types
B. The resonant frequency of a tuned circuit
C. The real frequency transmitted as opposed to the apparent frequency
D. Reflective force in antenna transmission lines
A. Radio frequency signals of all types
What is a usual name for electromagnetic waves that travel through space?
A. Gravity waves
B. Sound waves
C. Radio waves
D. Pressure waves
C. Radio waves
What is the formula used to calculate electrical power in a DC circuit?
A. Power (P) equals voltage (E) multiplied by current (I)
B. Power (P) equals voltage (E) divided by current (I)
C. Power (P) equals voltage (E) minus current (I)
D. Power (P) equals voltage (E) plus current (I)
A. Power (P) equals voltage (E) multiplied by current (I)
How much power is being used in a circuit when the applied voltage is 13.8 volts DC and the current is 10 amperes?
A. 138 watts
B. 0.7 watts
C. 23.8 watts
D. 3.8 watts
A. 138 watts
How much power is being used in a circuit when the applied voltage is 12 volts DC and the current is 2.5 amperes?
A. 4.8 watts
B. 30 watts
C. 14.5 watts
D. 0.208 watts
B. 30 watts
How many amperes are flowing in a circuit when the applied voltage is 12 volts DC and the load is 120 watts?
A. 0.1 amperes
B. 10 amperes
C. 12 amperes
D. 132 amperes
B. 10 amperes
What is meant by the term impedance?
A. It is a measure of the opposition to AC current flow in a circuit
B. It is the inverse of resistance
C. It is a measure of the Q or Quality Factor of a component
D. It is a measure of the power handling capability of a component
A. It is a measure of the opposition to AC current flow in a circuit
What are the units of impedance?
A. Volts
B. Amperes
C. Coulombs
D. Ohms
D. Ohms
What formula is used to calculate current in a circuit?
A. Current (I) equals voltage (E) multiplied by resistance (R)
B. Current (I) equals voltage (E) divided by resistance (R)
C. Current (I) equals voltage (E) added to resistance (R)
D. Current (I) equals voltage (E) minus resistance (R)
B. Current (I) equals voltage (E) divided by resistance (R)
What formula is used to calculate voltage in a circuit?
A. Voltage (E) equals current (I) multiplied by resistance (R)
B. Voltage (E) equals current (I) divided by resistance (R)
C. Voltage (E) equals current (I) added to resistance (R)
D. Voltage (E) equals current (I) minus resistance (R)
A. Voltage (E) equals current (I) multiplied by resistance (R)
What formula is used to calculate resistance in a circuit?
A. Resistance (R) equals voltage (E) multiplied by current (I)
B. Resistance (R) equals voltage (E) divided by current (I)
C. Resistance (R) equals voltage (E) added to current (I)
D. Resistance (R) equals voltage (E) minus current (I)
B. Resistance (R) equals voltage (E) divided by current (I)
What is the resistance of a circuit in which a current of 3 amperes flows through a resistor connected to 90 volts?
A. 3 ohms
B. 30 ohms
C. 93 ohms
D. 270 ohms
B. 30 ohms
What is the resistance in a circuit for which the applied voltage is 12 volts and the current flow is 1.5 amperes?
A. 18 ohms
B. 0.125 ohms
C. 8 ohms
D. 13.5 ohms
C. 8 ohms
What is the resistance of a circuit that draws 4 amperes from a 12-volt source?
A. 3 ohms
B. 16 ohms
C. 48 ohms
D. 8 Ohms
A. 3 ohms
What is the current flow in a circuit with an applied voltage of 120 volts and a resistance of 80 ohms?
A. 9600 amperes
B. 200 amperes
C. 0.667 amperes
D. 1.5 amperes
D. 1.5 amperes
What is the current flowing through a 100-ohm resistor connected across 200 volts?
A. 20,000 amperes
B. 0.5 amperes
C. 2 amperes
D. 100 amperes
C. 2 amperes
What is the current flowing through a 24-ohm resistor connected across 240 volts?
A. 24,000 amperes
B. 0.1 amperes
C. 10 amperes
D. 216 amperes
C. 10 amperes
What is the voltage across a 2-ohm resistor if a current of 0.5 amperes flows through it?
A. 1 volt
B. 0.25 volts
C. 2.5 volts
D. 1.5 volts
A. 1 volt
What is the voltage across a 10-ohm resistor if a current of 1 ampere flows through it?
A. 1 volt
B. 10 volts
C. 11 volts
D. 9 volts
B. 10 volts
What is the voltage across a 10-ohm resistor if a current of 2 amperes flows through it?
A. 8 volts
B. 0.2 volts
C. 12 volts
D. 20 volts
D. 20 volts