Efficiency
3 guided lessons · 27 checks · 4. Energy Resources and Energy Transfers → Energy Stores & Transfers
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Efficiency and the efficiency equation
Efficiency scores an energy transfer: what fraction of the output actually serves the purpose? It is the useful share of the output expressed as a percentage — and conservation of energy pins the total output to the total input, with the wasted share filling the gap.
What you know already
Efficiency turns the conservation law into a score: of all the energy leaving a device, how much served the purpose? This note fixes the equation, works a fan motor from 300 J to 72%, and teaches Sankey diagrams — the arrow picture where widths are joules and efficiency is visible at a glance.
Key points of understanding
- Efficiency scores how much of a transfer is wasted.
- Efficiency = (useful output) ÷ (total output) × 100%.
- High efficiency means most of the transferred energy is useful; low efficiency means most is wasted.
- By conservation of energy, what leaves equals what arrives.
- The output splits into the useful share plus the wasted share.
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1.Efficiency and the efficiency equation
Efficiency scores an energy transfer: what fraction of the output actually serves the purpose? It is the useful share of the output expressed as a percentage — and conservation of energy pins the total output to the total input, with the wasted share filling the gap.
Key points
- Efficiency scores how much of a transfer is wasted.
- Efficiency = (useful output) ÷ (total output) × 100%.
- High efficiency means most of the transferred energy is useful; low efficiency means most is wasted.
- By conservation of energy, what leaves equals what arrives.
- The output splits into the useful share plus the wasted share.
First pass
Guided content from the SME authoring corpus — note rn_vctGRbxP4NVz34JT, pinned at 8f834fff738f · promoted SyllabAI/syllabai-resources b3caaaa90c5e
