Electrical Basics Quiz

Simple Circuits

• To troubleshoot a simple circuit, check: battery placement, component connections, connection tightness, battery charge and voltage, and the functionality of the lightbulb.

Conductors and Insulators

• Conductors allow electricity to pass through them easily, insulators do not.
• Copper, gold, water, and graphite are conductors.
• Copper is cheap and a good conductor, gold is expensive and weaker.
• Water's conductivity is due to impurities, pure water is not conductive.
• Graphite is a weak conductor.
• Insulators prevent electric shock and include materials like plastic, wood, ceramic, glass and rubber.
• Plastic is man-made and a good insulator, it is used in electrical wirings, plugs and wall sockets.
• Wood is a natural insulator that does not conduct electricity.
• Ceramic and glass are used as barriers on pylons.
• Rubber is considered the best insulator and is used in electrician's gloves and protective clothes.

Electrical Current

• It is the movement of electrical charges through a conductor.
• The charges originate from an energy source, such as a battery.
• Electrical current requires a complete and unbroken pathway.

Components of a Simple Circuit

• A) Source of Energy: Provides energy, typically a cell or battery, converting chemical energy to electrical energy.
• B) Conducting Material: Transfers electrical energy, usually copper wires.
• C) Device: Converts electrical energy into useful output energy (heat, sound, light, or movement).

Types of Circuits

• A) Closed Circuit: An unbroken pathway for electricity to flow; a complete system for conducting electricity.
• B) Open Circuit: A broken pathway for electricity, stopping the flow; control devices like switches are used to intentionally break the pathway.

A Simple Circuit

• A single cell or battery is a source of electrical energy.
• A lightbulb converts electrical energy to light energy.
• Copper wire provides a pathway for electrical energy to travel.
• An open switch creates a gap in the pathway, stopping the flow of electricity.
• A closed switch allows electricity to flow.

Mains Electricity

• Energy comes from the sun and from fossil fuels.
• Fossil fuels are ancient plants and animal matter that have been transformed over millions of years.

How Fossil Fuels are Formed

• Fossil fuels are formed from the decomposition of plants and animals, which are buried under layers of sediment and subjected to heat and pressure over a long period.

Coal in South Africa

• South Africa has large coal deposits, particularly in Mpumalanga.
• The country operates over 20 coal-fired power stations, including Medupi and Duvha.

Fossil Fuels and Renewables

• Fossil fuels are non-renewable, meaning they cannot be replenished quickly.
• Renewable energy sources, like solar, wind, and hydro, are sustainable and environmentally friendly.

Key Energy Concepts

• A boiler heats water.
• A turbine produces electricity.
• A generator also produces electricity, using diesel or petrol.
• Electricity infrastructure encompasses power stations, coal mines, turbines, generators, and powerlines.

Ways to Save Energy in Homes

• Use a solar water geyser, gas geyser, or energy-saving light bulbs.
• Implement heat insulation and consider energy-saving tips like taking showers instead of baths, turning off appliances when not in use, covering pots while cooking, turning off lights when leaving a room and switching off geysers.

Renewable Energy Resources

• Renewable energy sources are eco-friendly, sustainable, and free to use, but the machinery involved can be expensive and unreliable.

Solar System

• The solar system comprises planets, moons, and objects that orbit our sun. The sun's gravity keeps these objects in motion around it.
• The Sun is a star that produces its own heat and light.
• Planets follow orbits around the sun, each with a unique path.
• Asteroids are chunks of rock that orbit the sun, concentrated in the asteroid belt between Mars and Jupiter.
• Planets are smaller than stars and cannot create their own light or heat, they reflect light from the star they orbit.
• Our solar system has eight planets categorized into inner rocky planets and outer gas planets.

Inner Rocky Planets

• The inner planets are closest to the sun and primarily composed of rocks and metals.
• Mercury, Venus, Earth, and Mars are the inner rocky planets.

Outer Gas Planets

• The outer gas planets are much bigger than the inner planets and mostly made up of swirling clouds and gas.
• Jupiter, Saturn, Uranus, and Neptune are the outer gas planets.
• All outer planets have rings composed of dust and ice.

Moon

• It orbits a planet, reflecting sunlight, and lacks water, air, or wind.

Asteroid vs Comet

• Asteroids are made of rocks and metal, while comets are made of ice, dust and rocky material.

Astronomer vs Astronaut

• Astronomers are scientists who study space objects.
• Astronauts are individuals who travel to space.

Key Space Concepts

• A crater forms when an asteroid impacts a planet or moon.
• An observatory is a building dedicated to observing space objects, typically with permanent markers.
• A telescope is a device used to observe and study space objects.

Mercury

• Mercury is the closest planet to the sun, the smallest and fastest planet, but not the hottest due to lacking an atmosphere.

Venus

• It's almost the same size as Earth, shines as brightly as the moon, and is the hottest planet in the solar system with an average temperature of 464°C.
• Venus has a thick atmosphere containing poisonous gases.

Earth

• The largest inner planet, a rocky planet with a significant amount of water, making it appear blue.
• Earth is the only known planet to support life.

Mars

• Often called the "red" planet due to the red dust that covers it.
• Mars has numerous volcanic mountains, including Olympus Mons, which is 28 km high.
• It experiences huge dust storms and is a cold, windy planet.

Jupiter

• The largest planet, mainly made from hydrogen and helium.
• Strong winds blow gasses creating streaks across the planet.
• The giant red spot on Jupiter is a massive storm of gasses.

Saturn

• Mostly made from hydrogen and helium, known for its prominent rings made from gas and ice.
• Saturn is so light that it would float on water and has 146 moons.

Uranus

• Made from hydrogen, helium, and methane, giving it a blue/green colour.
• Uranus is a frozen gas planet also known as the Ice giant.

Neptune

• A frozen planet with an average temperature of -200°C.
• Neptune is very windy, with speeds reaching 1400km an hour, and is blue/green due to the large amount of methane.

Orbiting the Sun

• All planets orbit the sun, those closer to the sun orbit faster. Mercury is the fastest, and Neptune is the slowest.
• It takes Earth 365¼ days to orbit the sun, which we call a year.
• Every four years, we have a leap year to account for the extra ¼ day accumulated.