6.1.3.A BasicsofElectricity

PROJECT LEAD THE WAY (PLTW)

Basics of Electric

What is Electricity?

  • Involves the movement of electrons.

  • Is invisible.

  • Provides light, heat, sound, and motion.

  • Has been practical for use over the last 100 years.

History of Electricity

Early Discoveries

  • 2500 years ago: Greeks discovered electricity by rubbing amber with other materials, attracting feathers and lightweight materials to the amber.

Benjamin Franklin's Insights

  • Suggested that opposite charges attract and like charges repel.

  • Formulated the Law of Charges, which explains why electrons stay bonded to the nucleus.

Electron Flow

  • An electron from one atom can knock out an electron from another atom.

  • Electricity is generated as electrons collide and transfer from one atom to another.

Water Analogy for Electricity

  • Tank: Represents the battery.

  • Pipe: Represents the wiring.

  • Faucet: Represents the switch.

Current

Definition

  • Current: The flow of electric charge.

Functionality

  • When the faucet (switch) is off, there is no flow (current).

  • When the faucet (switch) is on, there is flow (current).

Current in a Circuit

  • Off: No current flows.

  • On: Current flows through the circuit.

Voltage

Definition

  • Voltage: The force (pressure) behind the flow of current.

Functionality

  • When the faucet (switch) is off, there is pressure (voltage) pushing against the pipe and faucet.

  • When the faucet (switch) is on, pressure (voltage) pushes current through the system.

Voltage in a Circuit

  • The battery provides voltage that pushes current through the bulb when the switch is on.

Resistance

Definition

  • Resistance: The opposition to the flow of current.

Example

  • If a rock gets lodged in the pipe, flow (current) decreases.

Resistance in a Circuit

  • Resistors limit the flow of electricity, reducing the current and causing connected bulbs to become dimmer.

Types of Electricity

  • Static Electricity: Electrical charge an object develops due to an unequal number of protons and electrons.

  • Current Electricity: Movement of electrons through a conductor.

Static Electricity

  • Characteristics:

    • Uncontrollable.

    • Causes lightning, static cling, and "shocks" (e.g., wool socks on carpet).

Current Electricity

Types

  • Direct Current (DC): Electrons flow in the same direction (from negative to positive).

  • Alternating Current (AC): The movement of electrons changes direction.

Direct Current (DC)

  • Originates from batteries and can be converted from alternating current.

  • Commonly used in electronic devices (e.g., computers, cell phones).

Alternating Current (AC)

  • Produced by generators (e.g., coal, nuclear, hydroelectric, wind, and solar).

  • Used for powering motors, heaters, lights, and most wall-plugged devices.