A battery charger is connected to a $230\,\text{V}$ a.c. mains supply. It is then used to charge a $6.0\,\text{V}$ d.c. battery. Inside the charger are diodes and a transformer. What is the purpose of these components?
- Adiodes: rectify the a.c.; transformer: steps down the voltage
- Bdiodes: rectify the a.c.; transformer: steps up the voltage
- Cdiodes: step down the voltage; transformer: rectifies the a.c.
- Ddiodes: step up the voltage; transformer: rectifies the a.c.