Introduction to Electricity

What is Electricity?

• Electricity is the movement of electrons from one atom to another
• Produces an electric current

Types of Electricity

Natural Electricity: Lightning

• Lightning is an electric current, hotter than the surface of the sun
• Formed when ice particles in clouds bump and create charges
• Interaction of these charges with opposite charges on the ground produces lightning strikes

Man-Made Electricity

Batteries

• Direct Current (DC) power source
• Plus sign (+) for positive, minus sign (-) for negative
• Current flows in a loop from positive to negative
• Powers devices like game controllers, flashlights, phones, TV remotes

Fuel Cells

• Operate like batteries but don't need recharging
• Generate electricity through chemical reactions (e.g., hydrogen + oxygen)
• Can power large utilities to small devices, including hydrogen-powered vehicles like forklifts, cars, boats, buses

Solar Cells

• Use light from the sun to create electricity
• Found on rooftops of homes and buildings

Key Electrical Terms

• Watts: Measure of power consumed by a light
• Voltage: Measure of available power
• Amps: Speed of electron travel
• Wires: Shorter and thicker wires improve electron flow compared to longer, thinner wires

Alternating Current (AC)

• Electric current that reverses direction many times a second
• Originates from power plants
• Flows from power plants through power lines to homes, passes through transformers to adjust power level
• Circuit breaker in homes routes current to outlets and switches

Power Plants

• Thermal Power Plants: Use coal, biomass, petroleum, natural gas to heat water, creating steam to power generators
• Nuclear Power Plants: Use fission (splitting atoms) to produce steam
• Geothermal Power Plants: Use Earth's internal heat
• Hydro Power Plants: Use water flow to generate electricity
• Magnetic Field: Power plants use magnets to create electricity in generators, spinning coils of copper wire

Static Electricity

• Caused by movement of electrons between objects
• Example: Getting shocked after walking on carpet and touching a doorknob
• Example: Rubbing a balloon on hair and it sticking due to electron transfer

Conductors and Insulators

• Conductors: Allow electricity to flow (e.g., metals, water, trees, even humans)
• Insulators: Block electricity (e.g., plastic, glass, porcelain, rubber)
• Electrical wires use plastic or rubber insulation to prevent shocks

Historical Perspective

• Ancient Greeks discovered static electricity (~600 BC)
• Ancient batteries found in Roman sites (~1930s)
• Benjamin Franklin's experiments demonstrated connection between lightning and electricity

Summary

• Electricity powers many aspects of modern life
• Different methods of generation include natural occurrences (lightning) and man-made sources (batteries, fuel cells, solar cells, power plants)
• Safety around electricity is crucial, especially around conductors and insulators