A child has drawn the electric circuit to study Ohm's law as shown in figure. His teacher told that the circuit diagram needs correction. Study the circuit diagram and redraw it after making all corrections.

 

Three $2 \mathrm{\Omega }$ resistors, $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ are connected as shown in figure. Each of them dissipates energy and can with stand a maximum power of $18 \mathrm{W}$ without melting. Find the maximum current that can flow through the three resistors?

Should the resistance of an ammeter be low or high? Give reason.

What is the commercial unit of electrical energy? Represent it in terms of joules.

A current of 1 A flows in a series circuit containing an electric lamp and a conductor of $5 \mathrm{\Omega }$ when connected to a $10 \mathrm{v}$ battery. Calculate the resistance of the electric lamp.

Now, if a resistance of $10 \mathrm{\Omega }$ is connected in parallel with this series combination, what change (if any) in current flowing through $5 \mathrm{\Omega }$  conductor and potential difference across the lamp will take place? Give reason.

Why is parallel arrangement used in domestic wiring?