Energy Stores & TransfersEdexcel IGCSE Physics: Flashcards

Card 1 of 120 of 12 known

Question

Name the eight energy stores.

Tap or press Space to reveal

Tap card or press Space to flip

See all 12 cards

Name the eight energy stores.: Chemical, kinetic, gravitational, elastic, thermal, magnetic, electrostatic, nuclear.
Name the four energy transfer pathways.: Mechanically, electrically, by heating, by radiation.
State the principle of conservation of energy.: Energy cannot be created or destroyed, only transferred from one store to another.
State the equation for efficiency.: Efficiency = (useful energy output / total energy output) × 100%.
What does a Sankey diagram show?: Energy transfers, with the width of each arrow proportional to the amount of energy — showing useful output, wasted output and total input.
Define conduction.: Thermal energy transfer through a material by vibrating particles passing energy to neighbouring particles.
Define convection.: Thermal energy transfer in fluids caused by warmer, less dense fluid rising and cooler, denser fluid sinking.
Define radiation (thermal).: Thermal energy transfer by electromagnetic (infrared) waves, which can travel through a vacuum.
Why can convection not happen in solids?: Because the particles in a solid cannot flow/circulate to carry energy from place to place.
How do dark, matt surfaces compare to light, shiny surfaces for radiating heat?: Dark, matt surfaces are good emitters and absorbers of thermal radiation; light, shiny surfaces are poor emitters/absorbers.
Give one example of reducing unwanted energy transfer.: Using insulation (e.g. loft insulation) to reduce heat loss by conduction and convection.
A device is supplied with 500 J and usefully transfers 350 J. What is its efficiency?: Efficiency = (350/500) × 100% = 70%.