A coil carrying a heavy current and having large number of turns is mounted in a N-S vertical plane. A current flows in clockwise direction w.r.t to an observer towards east of the coil. A small magnetic needle at its center will have its north pole in

Situation:

Coil has many turns, carries heavy current.

Coil is in vertical plane facing North-South.

Current flows clockwise as seen by an observer standing to the east of the coil.

A small magnetic needle (like a compass) is placed at the center of the coil.

What happens to the needle?

• The current in the coil creates a magnetic field inside it.
• Using the Right-Hand Rule for magnetic field around current loops:
• Since current is clockwise from east side, inside the coil the magnetic field points towards the south.
• The magnetic needle aligns with the magnetic field.
• The north pole of the magnetic needle points towards the south of the coil.

In short:
Magnetic needle’s north pole points south inside the coil because of the coil’s magnetic field direction.