Force on a Straight Wire
Put a current-carrying wire in a magnetic field and it jumps. This simulation shows the force vector on the wire and lets you vary the angle between current and field, which is the part the simple F = BIL formula quietly assumes is 90°.
How to use this simulation
- Rotate the wire relative to the field direction
- Change the current, field strength and wire length
- Show or hide the force vector
What to look for
- Force follows a sine curve as you sweep the angle from 0° to 90°
- No force acts when the wire is parallel to the field
- Force scales linearly with current, field strength and length
The physics behind it
The force on a straight conductor is F = BIL·sinθ, where θ is the angle between the current and the field. It is maximum at 90° and vanishes when the wire lies along the field. The direction is perpendicular to both current and field, and is found with Fleming's left-hand rule.