The table shows the energy transfers for a machine before and after a modification.
| Test | Total energy input in J\mathrm{J}J | Useful energy output in J\mathrm{J}J |
|---|---|---|
| Before | 500 | 300 |
| After | 800 | 520 |
Which statement is correct?
Efficiency increases, and wasted energy per test decreases.
Efficiency increases, but wasted energy per test also increases.
Efficiency decreases, but wasted energy per test also decreases.
Efficiency decreases, and wasted energy per test increases.