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## Technician Class Exam Question Pool- Subelement T-5

SUBELEMENT T5 – Electrical principles: math for electronics; electronic principles; Ohm’s Law – [4 Exam Questions - 4 Groups]

T5A - Electrical principles, units, and terms: current and voltage; conductors and insulators; alternating and direct current; series and parallel circuits

T5A01

Electrical current is measured in which of the following units?

A. Volts

B. Watts

C. Ohms

D. Amperes

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T5A02

Electrical power is measured in which of the following units?

A. Volts

B. Watts

C. Ohms

D. Amperes

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T5A03

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

A. Voltage

B. Resistance

C. Capacitance

D. Current

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T5A04

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

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T5A05

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

A. Voltage

B. Ampere-hours

C. Capacitance

D. Inductance

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T5A06

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

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T5A07

Which of the following is a good electrical conductor?

A. Glass

B. Wood

C. Copper

D. Rubber

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T5A08

Which of the following is a good electrical insulator?

A. Copper

B. Glass

C. Aluminum

D. Mercury

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T5A09

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

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T5A10

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

A. Resistance

B. Current

C. Power

D. Voltage

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T5A11

What is the basic unit of electromotive force?

A. The volt

B. The watt

C. The ampere

D. The ohm

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T5A12

What describes the number of times per second that an alternating current reverses direction?

A. Pulse rate

B. Speed

C. Wavelength

D. Frequency

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T5A13

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

A. Series

B. Parallel

C. Resonant

D. Branch

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T5A14

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

A. Series

B. Parallel

C. Resonant

D. Branch

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T5B - Math for electronics: conversion of electrical units; decibels; the metric system

T5B01

How many milliamperes is 1.5 amperes?

A. 15 milliamperes

B. 150 milliamperes

C. 1,500 milliamperes

D. 15,000 milliamperes

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T5B02

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

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T5B03

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

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T5B04

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

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T5B05

Which of the following is equivalent to 500 milliwatts?

A. 0.02 watts

B. 0.5 watts

C. 5 watts

D. 50 watts

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T5B06

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

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T5B07

If a frequency display 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

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T5B08

How many microfarads are 1,000,000 picofarads?

A. 0.001 microfarads

B. 1 microfarad

C. 1000 microfarads

D. 1,000,000,000 microfarads

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T5B09

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

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T5B10

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

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T5B11

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

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T5B12

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

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T5B13

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

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T5C - Electronic principles: capacitance; inductance; current flow in circuits; alternating current; definition of RF; definition of polarity; DC power calculations; impedance

T5C01

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

A. Inductance

B. Resistance

C. Tolerance

D. Capacitance

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T5C02

What is the basic unit of capacitance?

A. The farad

B. The ohm

C. The volt

D. The henry

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T5C03

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

A. Admittance

B. Capacitance

C. Resistance

D. Inductance

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T5C04

What is the basic unit of inductance?

A. The coulomb

B. The farad

C. The henry

D. The ohm

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T5C05

What is the unit of frequency?

A. Hertz

B. Henry

C. Farad

D. Tesla

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T5C06

What does the abbreviation “RF” 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

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T5C07

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

A. Pressure

B. Electromagnetic

C. Gravity

D. Thermal

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T5C08

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)

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T5C09

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

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T5C10

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

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T5C11

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

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T5C12

What is 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

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T5C13

What are the units of impedance?

A. Volts

B. Amperes

C. Coulombs

D. Ohms

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T5D – Ohm’s Law: formulas and usage; components in series and parallel

T5D01

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)

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T5D02

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)

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T5D03

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)

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T5D04

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

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T5D05

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

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T5D06

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

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T5D07

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

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T5D08

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

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T5D09

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

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T5D10

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

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T5D11

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

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T5D12

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

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T5D13

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

A. It divides equally between them

B. It is unchanged

C. It divides based on the on the value of the components

D. The current in the second component is zero

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T5D14

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

A. It divides between them dependent on the value of the components

B. It is the same in both components

C. Its value doubles

D. Its value is halved

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T5D15

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

A. The same voltage as the source

B. Half the source voltage

C. It is determined by the type and value of the components

D. Twice the source voltage

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T5D16

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

A. It is determined by the type and value of the components

B. Half the source voltage

C. Twice the source voltage

D. The same voltage as the source

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