Four battery torches are tested. For each torch, the useful output is the light energy transferred. The remaining input energy is transferred in less useful ways.
| Torch | Useful light energy transfer in J | Total input energy transfer in J |
|---|---|---|
| J | 72 | 180 |
| K | 95 | 250 |
| L | 108 | 240 |
| M | 126 | 300 |
Which torch transfers the smallest proportion of its total input energy in less useful ways?
Torch L
Torch M
Torch J
Torch K
104 exam-style questions on AQA GCSE Physics 1.2 Conservation and dissipation of energy, covering 1.2.1 Energy transfers in a system and 1.2.2 Efficiency. Each one has a worked solution and a mark scheme showing where the marks go.