General Science Summative Test Reviewer - Energy, Electricity, Light, and Sound

Vocabulary practice flashcards covering terms and concepts from General Science Part I (Energy & Electricity) and Part II (Light & Sound).

Electricity generation

The process of converting different forms of energy, such as mechanical, thermal, and chemical energy, into electrical energy.

Power sector supply chain

The four-stage sequence through which electricity reaches consumers: Generation ($\text{G}$), Transmission ($\text{T}$), Distribution ($\text{D}$), and Utilization ($\text{U}$).

Renewable energy

Energy derived from natural resources that are replenished on a human timescale and generally produce little to no greenhouse gases.

Biomass

A renewable energy source that uses organic matter, such as wood, agricultural waste, and algae, to produce energy.

Geothermal energy

Energy harnessed from the Earth's internal heat, using steam or hot water deep underground to drive turbines and generate electricity.

Injection wells

Components of a geothermal energy system that return cooled water back underground.

Hydroelectric power

Energy generated by using the flow of water through turbines to drive a generator and produce electricity.

Solar energy

Energy captured from the Sun using methods such as photovoltaic (PV) cells or solar thermal systems.

Tidal energy

A predictable renewable energy source that uses the movement of ocean tides to generate electricity.

Wind energy

Energy generated by wind turbines harnessing the kinetic energy of moving air to spin turbine blades.

Non-renewable energy

Finite energy resources formed over millions of years that are not replenished on a human timescale.

Liquefied Natural Gas (LNG)

Natural gas cooled to a liquid state for storage and transport; it emits less $CO_2$ and fewer pollutants than coal and diesel.

Nuclear fission

The process of splitting atoms to release heat, which creates steam to drive turbines for electricity generation.

Intermittent energy sources

Energy sources, such as solar and wind, whose availability naturally varies over time.

Pumped Hydro Storage

An energy storage system that pumps water up to a reservoir during low electricity demand and releases it down through turbines during high demand.

Flywheels

Devices that store energy as rotational kinetic energy at high speeds and offer fast response times to help stabilize electrical grids.

Electrolysis

The chemical process using electricity to separate water into hydrogen and oxygen ($\text{Water} + \text{Electricity} \rightarrow \text{Hydrogen} + \text{Oxygen}$).

Electrical shock

A hazard that occurs when a person contacts a live electrical source, causing electric current to flow through the body.

Flashover

A dangerous phenomenon where fire rapidly spreads throughout an enclosed space once materials reach their ignition temperature.

Electrical fire

A fire caused when electrical current ignites flammable materials, which must never be extinguished with water.

Energy efficiency

Using less energy to accomplish the same task or achieve the same result.

5 Stars (Energy Label)

The highest star rating on an Energy Label Guide, indicating the maximum level of energy efficiency for an appliance or lighting product.

Wave

A disturbance that moves outward from a source and transfers energy as it travels.

Mechanical wave

A wave that requires a physical medium to travel through, such as sound.

Electromagnetic wave

A wave that does not require a medium and can travel through a vacuum at approximately $300,000\,km/s$, such as light.

Transverse wave

A wave in which the particle disturbance is perpendicular to the direction of wave travel.

Longitudinal wave

A wave in which the particle disturbance is parallel to the direction of wave travel.

Frequency

The number of wave occurrences per second, measured in Hertz ($Hz$); determines pitch in sound and color in light.

Wavelength

The distance between corresponding points on consecutive waves, commonly measured from peak to peak.

Period

The time required for one complete wave cycle to occur.

Doppler Effect

The observed change in wave frequency and wavelength resulting from relative motion between the source and the observer.

Redshift

The shift of light toward longer red wavelengths when an light source or galaxy moves away from the observer.

Blueshift

The shift of light toward shorter blue wavelengths when a light source moves closer to the observer.

Constructive interference

The interaction that occurs when two waves combine to form a larger wave with increased amplitude.

Destructive interference

The interaction that occurs when two waves combine in a manner that cancels each other out.

Sonic boom

An explosive sound produced when an aircraft travels faster than the speed of sound (Mach 1, approximately $1,234.8\,km/h$).

Soundproofing

The practice of reducing or eliminating unwanted noise through destructive interference, blocking, decoupling, and absorption.

Noise-cancelling headphones

Headphones that detect external noise using microphones and generate an out-of-phase sound wave to cancel it via destructive interference.

Ultrasound

Sound waves with frequencies above $20,000\,Hz$, exceeding the limit of human hearing.

SONAR

Acronym for Sound Navigation and Ranging; a technique that uses sound waves to detect objects, measure distances, and map underwater environments.

Active SONAR

A system that emits sound pulses into water and listens for returning echoes to locate objects.

Passive SONAR

A system that does not emit sound pulses, but only listens for sound waves produced by other sources.

Echolocation

The process of emitting sound waves and listening for returning echoes to determine the location, size, and texture of surrounding objects.

LED

Acronym for Light-Emitting Diode; a semiconductor device that generates light through electroluminescence.

Electroluminescence

The emission of light caused by electric current passing through a semiconductor, where electrons recombine with holes.

LASER

Acronym for Light Amplification by Stimulated Emission of Radiation; light that is coherent, monochromatic, and directional.

Holography

A technique that uses the interference pattern of split laser beams (object beam and reference beam) to generate three-dimensional images.

Fiber optics

Technology that transmits light signals through thin strands of glass or plastic using total internal reflection.

Total internal reflection

The complete reflection of light inside a medium, allowing light signals to travel long distances through optical fibers with minimal loss.

Photovoltaic cells

Devices that convert light energy directly into electrical energy using the photoelectric effect.

Photoelectric effect

The phenomenon in semiconductors where incoming photons excite electrons to produce an electric current.

LCD

Acronym for Liquid Crystal Display; technology that utilizes liquid crystals controlled by electric fields between polarizing filters to display images.

Optical microscope

An instrument that uses refraction through lenses to magnify minute objects.

Refracting telescope

A telescope that relies on lenses to gather and focus light from distant celestial objects.

Reflecting telescope

A telescope that utilizes curved mirrors to gather and focus light from distant objects.

Compound telescope

A telescope that combines both lenses and curved mirrors to gather and focus light.