Ham Radio (Amateur Radio)

A difference in which of the following causes electron flow?

Voltage

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

Current

Electrical current is measured in which of the following units?

Amperes

What type of current flow is opposed by resistance?

Direct current

Alternating current

RF current

Which of the following describes alternating current?

Current that alternates between positive and negative directions

What term describes the number of times per second that an alternating current makes a

complete cycle?

Frequency

What is the unit of frequency?

Hertz (Hz), which is equivalent to cycles per second.

Why are metals generally good conductors of electricity?

They have many free electrons

Which of the following is a good electrical insulator?

Glass

What formula is used to calculate voltage in a circuit?

E = I x R

What formula is used to calculate resistance in a circuit?

R = E / I

What formula is used to calculate current in a circuit?

I = E / R

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

1 volt

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

10 volts

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

20 volts

What is the resistance of a circuit in which a current of 3 amperes flows when connected to

90 volts?

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?

8 ohms

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

3 ohms

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

ohms?

1.5 amperes

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

2 amperes

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

10 amperes