Explain why aluminium resists corrosion but iron does not. Explain the term culling as used in livestock management. thr (a) (ii) State two methods of preventing iron from rusting [4 m: (6) (i) (ii) State three benefits of practising culling (5 m 172&1/pa/20

1. what is the si unit of emf? 2.a complete series circuit consists of a 12.0 v battery, a 4.70 ω resistor, and a switch in the closed position. the internal resistance of the battery is 0.30 ω. what does an ideal voltmeter read when placed across the resistor?