Question

The magnetic field produced by a current-carrying wire at a given point depends on

• A. the current passing through it.
• B. the voltage across it
• C. the power through it
• D. all

Answer 1

The correct option is A the current passing through it.

The magnetic field produced by a current-carrying wire at a given point depends directly on the current passing through it. Therefore, if there is a circular coil having n turns, the field produced is n times as large as that produced by a single turn. This is because the current in each circular turn has the same direction, and the field due to each turn then just adds up.