A straight copper wire of length $4.0\text{cm}$ carries a current of $6\text{A}$ and is placed in a uniform magnetic field of strength $0.30\text{T}$. The wire is perpendicular to the field. Find the magnitude of the magnetic force acting on the wire.

Step-by-step solution

1. Convert the length of the wire from centimetres to metres: $4.0\text{cm}=0.04\text{m}$.
2. Use the formula for the magnetic force on a straight conductor: $F=BIL$.
3. Substitute the given values: $F=0.30\text{T}\times 6\text{A}\times 0.04\text{m}$.
4. Carry out the multiplication: $0.30\times 6\times 0.04=0.072$.
5. The magnitude of the force is $0.072\text{N}$.

Concept tested: Magnetic force on straight conductor

Published 16 October 2026 · How this solution was prepared and checked