A pottery tests two heaters for drying thick blocks of damp clay evenly before the blocks are fired in a kiln. The clay contains water spread throughout it. One heater emits infrared and the other emits microwaves.
Each heater transfers the same total amount of energy to a block of clay. The table shows the temperature increase at two depths below the top surface of the block.
| Heater | Temperature increase at 0.5 cm depth in °C | Temperature increase at 3.0 cm depth in °C |
|---|---|---|
| A | 48 | 7 |
| B | 34 | 29 |
The pottery wants the temperature increase to be no more than 40 °C at 0.5 cm depth and at least 25 °C at 3.0 cm depth.
Explain which heater emits microwaves and justify which heater the pottery should select.
93 exam-style questions on AQA GCSE Physics 6.2 Electromagnetic waves, covering 6.2.1 Types of electromagnetic waves, 6.2.2 Properties of electromagnetic waves 1, 6.2.3 Properties of electromagnetic waves 2, 6.2.4 Uses and applications of electromagnetic waves, 6.2.5 Lenses, and 6.2.6 Visible light. Each one has a worked solution and a mark scheme showing where the marks go.