Science (086) — AI-generated practice question

Near the wire of the loop, the magnetic field lines form small concentric circles around the wire. As we move towards the centre of the loop, these circles grow larger and larger. By the time we reach the centre, the arcs of these large circles appear as straight parallel lines.

At the centre, the field looks like straight lines passing through the loop. Every section of the wire contributes to the field in the same direction at the centre (verified by right-hand rule). The field at the centre is directed perpendicular to the plane of the loop (along the axis of the loop).

Source: Chapter 12, Section 12.2.3 — Magnetic Field due to a Current through a Circular Loop

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• Examiners look for three key points: (1) concentric circles near wire → becoming larger → straight lines at centre, (2) all contributions add in the same direction, (3) field is perpendicular to the plane of the loop.
• The phrase "arcs of big circles appear as straight lines" is directly from the textbook — use it.
• Don't confuse "perpendicular to the plane" with "parallel to the plane" — the field at the centre is along the axis, i.e., perpendicular to the loop's plane.