What constitutes the field of a magnet?

In domestic electrical wiring,what is the red-colored insulated wire used for?

Meena draws magnetic field lines of a field close to the axis of a current-carrying circular loop. As she moves away from the centre of the circular loop,she observes that the lines keep on diverging. How will you explain her observation?

Two long parallel wires are hanging freely. If they are connected to a battery $(i)$ in series and $(ii)$ in parallel,what would be the effect on their positions?

Inside a solenoid,the magnetic field is constant in magnitude and direction.

$A$ coil of insulated wire is connected to a galvanometer. Explain what happens if a bar magnet with its north pole towards one face of the coil is:
$(i)$ moved quickly towards the coil,
$(ii)$ kept stationary inside the coil,and
$(iii)$ moved quickly away from the coil?