Figure 4 shows the features of an x-rays tube.
![Physcf4et1p2q18b](https://www.easyelimu.com/images/form_4_past_papers/Form4_EndTerm1_2021/Physc_Paper_1_2_3/Physcf4et1p2q18b.JPG)
- Name the parts labelled A and B.
- Explain how a change in potential across PQ changes the intensity of the x-rays produced in the tube.
- During the operation of the tube, the target becomes very hot. Explain how this heat is caused.