Lesson 10 Quiz: Basic Electrical Concepts

1. Which term describes the rate at which electrical energy is used? Choose only ONE best answer.

• A. Resistance

• B. Current

• C. Power

• D. Voltage

Answer explanation

This answer is correct.

Power is calculated as electromotive force times electrical current: Amps times Volts equals Watts.

2. What is the unit of frequency? Choose only ONE best answer.

• A. Hertz

• B. Henry

• C. Farad

• D. Tesla

Answer explanation

This answer is correct.

Hertz are the units of frequency in the International System of Units, and in amateur radio are used to describe electromagnetic radiation. They can be measured using tools that count frequency, including an oscilloscope. The symbol for Hertz is Hz.

Tags

NGSS.HS-PS4-1

3. Which of the following is a good electrical insulator? Choose only ONE best answer.

• A. Copper

• B. Glass

• C. Aluminum

• D. Mercury

Answer explanation

This answer is correct.

Glass is a good example of an electrical insulator. Glass is used on many high-voltage power distribution systems. Copper is an example of a good conductor.

Tags

NGSS.HS-PS1-3

NGSS.HS-PS2-6

4. What band is best suited for communicating via meteor scatter? Choose only ONE best answer.

• A. Series

• B. Parallel

• C. Resonant

• D. Branch

Answer explanation

This answer is correct.

A series circuit only has one path for the current to flow, so DC current is the same through all the components, however voltage may drop. A parallel circuit has sections so the current divides when flowing through the different areas.

Tags

NGSS.HS-PS4-5

5. Electrical power is measured in which of the following units? Choose only ONE best answer.

• A. Volts

• B. Watts

• C. Watt-hours

• D. Amperes

Answer explanation

This answer is correct.

Electrical power is measured in watts, or sometimes kilowatts. (1 kilowatt is equal to 1,000 watts). A single watt is defined as the electrical power equal to one ampere at one volt. In Ohm's Law, Power = Amps times Volts.

6. What is impedance? Choose only ONE best answer.

• 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

Answer explanation

This answer is correct.

Impedance is a unit of measure of the opposition to AC current flow in a circuit. In a DC circuit, the opposition of flow would be called resistance.

7.  What describes the number of times per second that an alternating current makes a complete cycle? Choose only ONE best answer.

• A. Pulse rate

• B. Speed

• C. Wavelength

• D. Frequency

Answer explanation

This answer is correct.

Frequency is defined as the number of times per second an alternating current completes a full cycle. Frequency is measured in cycles per second or Hz (Hertz). One CPS (cycle per second) = 1 Hz.

Tags

NGSS.HS-PS4-1

8.  What is the name for the flow of electrons in an electric circuit? Choose only ONE best answer.

• A. Voltage

• B. Resistance

• C. Capacitance

• D. Current

Answer explanation

This answer is correct.

The flow of electrons in an electrical circuit defines current. Current or amps is the rate of flow of electrons in an electrical circuit.

9. Electrical current is measured in which of the following units? Choose only ONE best answer.

• A. Volts

• B. Watts

• C. Ohms

• D. Amperes

Answer explanation

This answer is correct.

Electric current is measured in amperes, or amps. An ampere is the rate of flow of electrons. The flow rate of one coulomb per second is equal to one amp of current. You measure current flow with an amp meter connected in series with the electrical circuit. Many times you will see electrical current referenced as "A."

10. What is the ability to store energy in an electric field called? Choose only ONE best answer.

• A. Inductance

• B. Resistance

• C. Tolerance

• D. Capacitance

Answer explanation

This answer is correct.

When the capacitor is discharged, the potential energy stored in the electric field is converted to the charge.