Sub-Element T5 Electrical principles [4 Exam Questions]

Question 1

Electrical current is measured in which of the following units?

Answer 1

Amperes

Question 2

Electrical power is measured in which of the following units?

Answer 2

Watts

Question 3

What is the name for the flow of electrons in an electric circuit?

Answer 3

Current

Question 4

What is the name for a current that flows only in one direction?

Answer 4

Direct current

Question 5

What is the electrical term for the electromotive force (EMF) that causes electron flow?

Answer 5

Voltage

Question 6

How much voltage does a mobile transceiver typically require?

Answer 6

About 12 volts

Question 7

Which of the following is a good electrical conductor?

Answer 7

Copper

Question 8

Which of the following is a good electrical insulator?

Answer 8

Glass

Question 9

What is the name for a current that reverses direction on a regular basis?

Answer 9

Alternating current

Question 10

Which term describes the rate at which electrical energy is used?

Answer 10

Power

Question 11

What is the unit of electromotive force?

Answer 11

The volt

Question 12

What describes the number of times per second that an alternating current makes a complete cycle?

Answer 12

Frequency

Question 13

In which type of circuit is current the same through all components?

Answer 13

Series

Question 14

In which type of circuit is voltage the same across all components?

Answer 14

Parallel

Question 15

How many milliamperes is 1.5 amperes?

Answer 15

1500 milliamperes

Question 16

What is another way to specify a radio signal frequency of 1,500,000 hertz?

Answer 16

1500 kHz

Question 17

How many volts are equal to one kilovolt?

Answer 17

One thousand volts

Question 18

How many volts are equal to one microvolt?

Answer 18

One one-millionth of a volt

Question 19

Which of the following is equal to 500 milliwatts?

Answer 19

0.5 watts

Question 20

If an ammeter calibrated in amperes is used to measure a 3000-milliampere current, what reading would it show?

Answer 20

3 amperes

Question 21

If a frequency display calibrated in megahertz shows a reading of 3.525 MHz, what would it show if it were calibrated in kilohertz?

Answer 21

3525 kHz

Question 22

How many microfarads are equal to 1,000,000 picofarads?

Answer 22

1 microfarad

Question 23

What is the approximate amount of change, measured in decibels (dB), of a power increase from 5 watts to 10 watts?

Answer 23

3 dB

Question 24

What is the approximate amount of change, measured in decibels (dB), of a power decrease from 12 watts to 3 watts?

Answer 24

-6 dB

Question 25

What is the amount of change, measured in decibels (dB), of a power increase from 20 watts to 200 watts?

Answer 25

10 dB

Question 26

Which of the following frequencies is equal to 28,400 kHz?

Answer 26

28.400 MHz

Question 27

If a frequency display shows a reading of 2425 MHz, what frequency is that in GHz?

Answer 27

2.425 GHz

Question 28

What is the ability to store energy in an electric field called?

Answer 28

Capacitance

Question 29

What is the basic unit of capacitance?

Answer 29

The farad

Question 30

What is the ability to store energy in a magnetic field called?

Answer 30

Inductance

Question 31

What is the basic unit of inductance?

Answer 31

The henry

Question 32

What is the unit of frequency?

Answer 32

Hertz

Question 33

What does the abbreviation "RF" refer to?

Answer 33

Radio frequency signals of all types

Question 34

A radio wave is made up of what type of energy?

Answer 34

Electromagnetic

Question 35

What is the formula used to calculate electrical power in a DC circuit?

Answer 35

Power (P) equals voltage (E) multiplied by current (I)

Question 36

How much power is being used in a circuit when the applied voltage is 13.8 volts DC and the current is 10 amperes?

Answer 36

138 watts

Question 37

How much power is being used in a circuit when the applied voltage is 12 volts DC and the current is 2.5 amperes?

Answer 37

30 watts

Question 38

How many amperes are flowing in a circuit when the applied voltage is 12 volts DC and the load is 120 watts?

Answer 38

10 amperes

Question 39

What is impedance?

Answer 39

A measure of the opposition to AC current flow in a circuit

Question 40

What is a unit of impedance?

Answer 40

Ohms

Question 41

What is the proper abbreviation for megahertz?

Answer 41

MHz

Question 42

What formula is used to calculate current in a circuit?

Answer 42

Current (I) equals voltage (E) divided by resistance (R)

Question 43

What formula is used to calculate voltage in a circuit?

Answer 43

Voltage (E) equals current (I) multiplied by resistance (R)

Question 44

What formula is used to calculate resistance in a circuit?

Answer 44

Resistance (R) equals voltage (E) divided by current (I)

Question 45

What is the resistance of a circuit in which a current of 3 amperes flows through a resistor connected to 90 volts?

Answer 45

30 ohms

Question 46

What is the resistance in a circuit for which the applied voltage is 12 volts and the current flow is 1.5 amperes?

Answer 46

8 ohms

Question 47

What is the resistance of a circuit that draws 4 amperes from a 12-volt source?

Answer 47

3 ohms

Question 48

What is the current in a circuit with an applied voltage of 120 volts and a resistance of 80 ohms?

Answer 48

1.5 amperes

Question 49

What is the current through a 100-ohm resistor connected across 200 volts?

Answer 49

2 amperes

Question 50

What is the current through a 24-ohm resistor connected across 240 volts?

Answer 50

10 amperes

Question 51

What is the voltage across a 2-ohm resistor if a current of 0.5 amperes flows through it?

Answer 51

1 volt

Question 52

What is the voltage across a 10-ohm resistor if a current of 1 ampere flows through it?

Answer 52

10 volts

Question 53

What is the voltage across a 10-ohm resistor if a current of 2 amperes flows through it?

Answer 53

20 volts

Question 54

What happens to current at the junction of two components in series?

Answer 54

It is unchanged

Question 55

What happens to current at the junction of two components in parallel?

Answer 55

It divides between them dependent on the value of the components

Question 56

What is the voltage across each of two components in series with a voltage source?

Answer 56

It is determined by the type and value of the components

Question 57

What is the voltage across each of two components in parallel with a voltage source?

Answer 57

The same voltage as the source