01. Electric Quantity

Energy transferred per unit charge.

Voltage

The difference in electric potential between two points.

Potential Difference (pd)

Energy supplied per unit charge by a source.

Electromotive Force (emf)

The rate at which electric charge flows per unit time.

Current

Electric charge flows in one direction.

Direct Current (DC)

Electric charge periodically reverses direction.

Alternating Current (AC)

The measure of opposition to the flow of electric current.

Resistance

Resistivity (Type of Material) to resistance

Directly proportional to resistance.

Length of the Conductor to resistance

Directly proportional to resistance.

Cross-sectional Area of the Conductor to resistance

Inversely proportional to resistance.

Temperature to resistance

Directly proportional to resistance in most metals.

The relationship among current, voltage, and resistance.

Ohm’s Law

Current is directly proportional to voltage and inversely proportional to resistance, at constant resistance or voltage, respectively.

Ohm’s Law

The rate at which electrical energy is transferred or used.

Electric Power

What is a conductor?

A material that readily allows electric current to flow.

What type of resistance do conductors have?

Low electrical resistance.

Why do conductors allow current to flow easily?

They have loosely bound electrons that move freely.

What is an insulator?

A material that strongly resists electric current.

What type of resistivity do insulators have?

High electrical resistivity.

Why do insulators resist current flow?

Their electrons are tightly bound to atoms.

What happens to a semiconductor at very low temperatures?

It behaves more like an insulator.

What can increase the conductivity of a semiconductor?

Heat, light, applied voltage, or added impurities.

What is doping in semiconductors?

Adding impurities to change electrical conductivity.

What is conductance?

A measure of how easily electric current flows through a material.

What is the relationship between conductance and resistance?

They are inversely proportional.

What is the relationship between resistance and conductance?

Resistance increases → conductance decreases.