Technicial License - Electrical Principals Flashcards
T5A05 (Pg. 4)
What is the electrical term for the force that causes electron flow?
A. Voltage <—-
B. Ampere-hours
C. Capacitance
D. Inductance
A. Voltage <—-
B. Ampere-hours
C. Capacitance
D. Inductance
What causes energy to flow through a circuit? (Pg. 4)
VOLTAGE (V) wired to RESISTOR (R) causes CURRENT (I) (energy) to flow through CIRCUIT.
Force that causes electrons to flow in a circuit.
Measured in volts;
V represents both the force and the units. (Pg. 4)
Voltage
Electromotive Force or Electrical Potential;
Electromotive Force & Electric Potential measured in (Pg. 4)
Volts
T5A03 (Pg. 5)
What is the name for the flow of electrons in an electric circuit?
A. Voltage
B. Resistance
C. Capacitance
D. CURRENT <—-
T5A01 (Pg. 5)
Electrical current is measured in which of the following units?
A. Volts
B. Watts
C. Ohms
D. AMPERES <—-
T5A09 (Pg. 6)
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
T5A12 (Pg. 6)
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 <—-
T5A06 (Pg. 6)
What is the unit of frequency?
A. HERTZ <—-
B. Henry
C. Farad
D. Tesla
T5A04 (Pg. 6)
What are the units of electrical resistance?
A. Siemens
B. Mhos
C. OHMS <—-
D. Coulombs
T5A11 (Pg. 6)
What type of current flow is opposed by resistance?
A. Direct current
B. Alternating current
C. RF current
D. ALL THESE CHOICES ARE CORRECT <—-
T5A07 (Pg.7)
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
T5A08 (Pg. 7)
Which of the following is a good electrical insulator?
A. Copper
B. GLASS <—-
C. Aluminum
D. Mercury
T5D02 (Pg. 8)
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
Using simple algebra, you can derive the other two forms of this equation: R = E / I and I = E / R.
These two equations let you calculate the resistance in a circuit if you know the voltage and current or
the current in a circuit if you know the voltage and resistance.
T5D03 (Pg. 8)
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
T5D01 (Pg. 8)
What formula is used to calculate current in a circuit?
A. I = E R
B. I = E / R <—-
C. I = E + R
D. I = E - R
T5D04 (Pg. 8)
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
Here’s how to calculate this answer: R = E / I = 90 volts / 3 amperes = 30 ohms.
T5D05 (Pg. 9)
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
R = E / I = 12 volts / 1.5 amperes = 8 ohms
T5D06 (Pg. 9)
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
R = E / I = 12 volts / 4 amperes = 3 ohms.
T5D07 (Pg. 9)
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 <—-
I = E / R = 120 volts / 80 ohms = 1.5 amperes.
T5D08 (Pg. 9)
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
I = E / R = 200 volts / 100 ohms = 2 amperes.
T5D09 (Pg. 9)
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
I = E / R = 240 volts / 24 ohms = 10 amperes.
T5D10 (Pg. 10)
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
E = I × R = 0.5 amperes × 2 ohms = 1 volt.
T5D11 (Pg. 10)
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
E = I × R = 1 amperes × 10 ohms = 10 volts.
T5D12 (Pg. 10)
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 <—-
E = I × R = 2 amperes × 10 ohms = 20 volts.
T5D13 (Pg. 11)
In which type of circuit is DC current the same through all components?
A. Series <—–
B. Parallel
C. Resonant
D. Branch
T5D14 (Pg. 12)
In which type of circuit is voltage the same across all components?
A. Series
B. Parallel <—–
C. Resonant
D. Branch
T5A10 (Pg. 13)
Which term describes the rate at which electrical energy is used?
A. Resistance
B. Current
C. Power <—-
D. Voltage
T5A02 (Pg. 13)
Electrical power is measured in which of the following units?
A. Volts
B. Watts <—–
C. Watt-hours
D. Amperes
T5C08 (Pg. 13)
What is the formula used to calculate electrical power (P) in a DC circuit?
A. P = E x I <——
B. P = E / I
C. P = E – I
D. P = E + I
T5C09 (Pg. 13)
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
The calculation for this question is P = E × I = 13.8 V × 10 A = 138 W.
T5C10 (Pg. 13)
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
The calculation for this question is P = E × I = 12 V × 2.5 A = 30 W
T5C11 (Pg. 14)
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
The calculation for this question is I = P / E = 120 W / 12 V = 10 A
T5B01 (Pg. 15)
How many milliamperes is 1.5 amperes?
A. 15 milliamperes
B. 150 milliamperes
15
C. 1500 milliamperes <——
D. 15,000 milliamperes
To convert amperes to milliamperes, you multiply by 1,000.
T5B02 (Pg. 16)
Which is equal to 1,500,000 hertz?
A. 1500 kHz <——
B. 1500 MHz
C. 15 GHz
D. 150 kHz
To convert from hertz (Hz) to kHz, you divide by 1,000.
T5B03 (Pg. 16)
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
T5B04 (Pg. 16)
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
To convert from kilovolts to volts, you multiply by 1,000.
To convert from microvolts to volts, you divide by one million
T5B05 (Pg. 16)
Which is equal to 500 milliwatts?
A. 0.02 watts
B. 0.5 watts <—-
C. 5 watts
D. 50 watts
To convert from milliwatts to watts, you divide by 1,000. 500 / 1000 = ½ or 0.5.
T5B06 (Pg. 16)
Which is equal to 3000 milliamperes?
A. 0.003 amperes
B. 0.3 amperes
C. 3,000,000 amperes
D. 3 amperes <—-
There are a thousand milliamperes in an ampere, so to convert from milliamperes to amperes, you
divide by 1,000.
T5C13 (Pg. 17)
16
What is the abbreviation for kilohertz?
A. KHZ
B. khz
C. khZ
D. kHz <—-
1 kHz is 1,000 Hz or 1,000 cycles per second. Note that the “H” in Hz is capitalized. 1,000,000 cycles
per second is 1,000 kHz, or 1 MHz.
T5C07 (Pg. 17)
What is the abbreviation for megahertz?
A. MH
B. mh
C. Mhz
D. MHz <—-
T5B07 (Pg. 17)
Which is equal to 3.525 MHz?
A. 0.003525 kHz
B. 35.25 kHz
C. 3525 kHz <—-
D. 3,525,000 kHz
T5B12 (Pg. 17)
Which is equal to 28400 kHz?
A. 28.400 kHz
B. 2.800 MHz
C. 284.00 MHz
D. 28.400 MHz <—-
T5B13 (Pg. 17)
Which is equal to 2425 MHz?
A. 0.002425 GHz
B. 24.25 GHz
C. 2.425 GHz <—-
D. 2425 GHz
To convert from MHz to kHz, you multiply by 1,000.
To convert from kHz to MHz, or to convert from MHz to GHz, you divide by 1,000.
T5B08
Which is equal to 1,000,000 picofarads?
A. 0.001 microfarads
B. 1 microfarad
C. 1000 microfarads
D. 1,000,000,000 microfara
