A circular coil has 50 turns of wire. How does the magnetic field at its centre compare to that produced by a…

Question

A circular coil has 50 turns of wire. How does the magnetic field at its centre compare to that produced by a single-turn coil carrying the same current? Give a reason for your answer.

Accepted Answer

## Model Answer The magnetic field at the centre of the 50-turn coil is **50 times** greater than that produced by a single-turn coil carrying the same current. **Reason:** The current in each turn flows in the same direction, so the magnetic field due to each turn adds up. Therefore, the total field is $n$ times that of a single turn, where $n = 50$. *Source: Chapter 12, Section 12.2.3 – Magnetic Field due to a Current through a Circular Loop* --- ## Explanation The key statement from the textbook is: *"If there is a circular coil having n turns, the field produced is n times as large as that produced by a single turn, because the current in each circular turn has the same direction, and the field due to each turn just adds up."* Examiners expect you to state the multiplying factor (50×) **and** give the reason (same direction → fields add up). Both parts are needed for full marks.

Science (086) — AI-generated practice question