What is the resistance of an ideal ammeter?

8 Explain what is electric potential and potential difference. 9 A current of 0.5A flows through a conductor having resistance of 10 ohms for ½ hr. Find the amount of electric energy consumed by this conductor. 11 Which one has more resistance –a 100 watt bulb or 60 watt bulb? 12 Define the principle of conservation of electric charge. Explain it with an example.