A wire hangs between magnet poles. The switch closes and a current flows. What happens to the wire?
A straight wire runs between the poles of a horseshoe magnet, carrying a steady current. The wire can be held at any angle. The current and the magnets stay the same throughout. Only the wire's angle changes.
First, the wire lies straight across the field lines, perpendicular to them. The force on it is at its largest.
The wire is tilted to a slant across the field lines. There is still a force, but it is smaller.
The wire lies along the field lines, parallel to them. The force is zero.
The current is reversed while the wire lies parallel to the field. The force is still zero.
So the angle between the current and the field lines decides the size of the force.
A current-carrying wire lies along the field lines. Does it feel a force?
A current-carrying wire runs straight across the field lines. Does it feel a force?
A rod carrying a current is laid along the field lines of a large magnet. What force does it feel?
The current runs parallel to the field lines.
Parallel to the field, the motor-effect force is zero.
The rod feels no force.
The same rod is turned so the current runs straight across the field lines. What happens to the force?
The current now runs perpendicular to the field.
Perpendicular to the field, the motor-effect force is at its largest.
The force grows from zero to its largest.
A student says the force is largest when the current runs straight across the field lines. Is the student correct?
A current-carrying wire sits in a magnetic field. In which position is the force on it largest?
A current-carrying wire starts straight across the field lines and is slowly turned until it lies along them. What happens to the force?
A current-carrying wire lies along the field lines and feels no force. Which change gives it a force?