Electrical Principles 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. Watt-hours
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 are the units of electrical resistance?
A. Siemens
B. Mhos
C. Ohms
D. Coulombs
C. Ohms
What is the electrical term for the force that causes electron flow?
A. Voltage
B. Ampere-hours
C. Capacitance
D. Inductance
A. Voltage
What is the unit of frequency?
A. Hertz
B. Henry
C. Farad
D. Tesla
A. Hertz
Why are metals generally good conductors of electricity?
A. They have relatively high density
B. They have many free electrons
C. They have many free protons
D. All these choices are correct
B. They have many free electrons
Which of the following is a good electrical insulator?
A. Copper
B. Glass
C. Aluminum
D. Mercury
B. Glass
Which of the following describes alternating current?
A. Current that alternates between a positive direction and zero
B. Current that alternates between a negative direction and zero
C. Current that alternates between positive and negative directions
D. All these answers are correct
C. Current that alternates between positive and negative directions
Which term describes the rate at which electrical energy is used?
A. Resistance
B. Current
C. Power
D. Voltage
C. Power
What type of current flow is opposed by resistance?
A. Direct current
B. Alternating current
C. RF current
D. All these choices are correct
D. All these choices are correct
What describes the number of times per second that an alternating current makes a complete cycle?
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. 1500 milliamperes
D. 15,000 milliamperes
C. 1500 milliamperes
Which is equal to 1,500,000 hertz?
A. 1500 kHz
B. 1500 MHz
C. 15 GHz
D. 150 kHz
A. 1500 kHz
Which is 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
Which is 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 is equal to 500 milliwatts?
A. 0.02 watts
B. 0.5 watts
C. 5 watts
D. 50 watts
B. 0.5 watts
Which is equal to 3000 milliamperes?
A. 0.003 amperes
B. 0.3 amperes
C. 3,000,000 amperes
D. 3 amperes
D. 3 amperes
Which is equal to 3.525 MHz?
A. 0.003525 kHz
B. 35.25 kHz
C. 3525 kHz
D. 3,525,000 kHz
C. 3525 kHz
Which is equal to 1,000,000 picofarads?
A. 0.001 microfarads
B. 1 microfarad
C. 1000 microfarads
D. 1,000,000,000 microfarads
B. 1 microfarad
Which decibel value most closely represents a power increase from 5 watts to 10 watts?
A. 2 dB
B. 3 dB
C. 5 dB
D. 10 dB
B. 3 dB
Which decibel value most closely represents a power decrease from 12 watts to 3 watts?
A. -1 dB
B. -3 dB
C. -6 dB
D. -9 dB
C. -6 dB
Which decibel value represents 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 is equal to 28400 kHz?
A. 28.400 kHz
B. 2.800 MHz
C. 284.00 MHz
D. 28.400 MHz
D. 28.400 MHz
Which is equal to 2425 MHz?
A. 0.002425 GHz
B. 24.25 GHz
C. 2.425 GHz
D. 2425 GHz
C. 2.425 GHz
What describes the ability to store energy in an electric field?
A. Inductance
B. Resistance
C. Tolerance
D. Capacitance
D. Capacitance
What is the unit of capacitance?
A. The farad
B. The ohm
C. The volt
D. The henry
A. The farad
What describes the ability to store energy in a magnetic field?
A. Admittance
B. Capacitance
C. Resistance
D. Inductance
D. Inductance
What is the unit of inductance?
A. The coulomb
B. The farad
C. The henry
D. The ohm
C. The henry
What is the unit of impedance?
A. The volt
B. The ampere
C. The coulomb
D. The ohm
D. The ohm
What does the abbreviation “RF” mean?
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 the abbreviation for megahertz?
A. MH
B. mh
C. Mhz
D. MHz
D. MHz
What is the formula used to calculate electrical power (P) in a DC circuit?
A. P = I x E
B. P = E / I
C. P = E – I
D. P = I + E
A. P = I x E
How much power is delivered by a voltage of 13.8 volts DC and a current of 10 amperes?
A. 138 watts
B. 0.7 watts
C. 23.8 watts
D. 3.8 watts
A. 138 watts
How much power is delivered by a voltage of 12 volts DC and a current of 2.5 amperes?
A. 4.8 watts
B. 30 watts
C. 14.5 watts
D. 0.208 watts
B. 30 watts
How much current is required to deliver 120 watts at a voltage of 12 volts DC?
A. 0.1 amperes
B. 10 amperes
C. 12 amperes
D. 132 amperes
B. 10 amperes
What is impedance?
A. The opposition to AC current flow
B. The inverse of resistance
C. The Q or Quality Factor of a component
D. The power handling capability of a component
A. The opposition to AC current flow
What is the abbreviation for kilohertz?
A. KHZ
B. khz
C. khZ
D. kHz
D. kHz
What formula is used to calculate current in a circuit?
A. I = E x R
B. I = E / R
C. I = E + R
D. I = E - R
B. I = E / R
What formula is used to calculate voltage in a circuit?
A. E = I x R
B. E = I / R
C. E = I + R
D. E = I - R
A. E = I x R
What formula is used to calculate resistance in a circuit?
A. R = E x I
B. R = E / I
C. R = E + I
D. R = E - I
B. R = E / I
What is the resistance of a circuit in which a current of 3 amperes flows when connected to 90 volts?
A. 3 ohms
B. 30 ohms
C. 93 ohms
D. 270 ohms
B. 30 ohms
What is the resistance of 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 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 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 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
In which type of circuit is DC current the same through all components?
A. Series
B. Parallel
C. Resonant
D. Branch
A. Series
In which type of circuit is voltage the same across all components?
A. Series
B. Parallel
C. Resonant
D. Branch
B. Parallel
