SYMBOLS AND TERMS
LAWS
AC AND DC SYSTEMS
REACTANCE AND IMPEDANCE
POWER TRANSMISSION
100

This unit measures electrical current.

What is an ampere?

100

According to Ohm’s Law, voltage equals this times resistance.

What is current?

100

This type of current periodically reverses direction.

What is AC?

100

This type of reactance occurs in circuits with inductors.

What is inductive reactance?

100

Power is calculated using this formula.

What is P = VI?

200

This property resists the flow of electricity.

What is resistance?

200

Kirchhoff’s first law states that the sum of currents at a junction is always this.

What is zero?

200

Car batteries typically use this type of current.

What is DC?

200

Impedance combines these two properties.

What are resistance and reactance?

200

Long-distance transmission lines use this type of current.

What is AC?

300

The ability of a component to store electrical energy.

What is capacitance?

300

In a 24V circuit with 8A current, the resistance is this.

What is 3 ohms?

300

The effect where AC current concentrates near the outer conductor.

What is the skin effect?

300

The equation Z² = R² + X² represents this concept.

What is impedance?

300

AC power is converted to DC using this device.

What is a rectifier?

400

The formula P = VI represents this quantity.

What is power?

400

Kirchhoff’s second law states that the sum of voltages in a closed loop is always this.

What is zero?

400

AC circuits have this property that opposes current flow.

What is reactance?

400

In a circuit with R = 5Ω, XL = 10Ω, and XC = 3Ω, impedance is this.

What is 8.6Ω?

400

High-voltage power transmission reduces this electrical loss.

What is heat loss?

500

The simplest way to show an electrical circuit.

What is a ladder diagram?

500

What is the total resistance of two parallel resistors, 5Ω and 10Ω?

What is 3.34Ω?

500

The frequency of standard household AC power in the U.S.

What is 60 Hz?

500

The formula for inductive reactance.

What is XL = 2πfL?

500

The three-phase system delivers more power than this type of system.

What is single-phase?