Electromagnetic Force

Question 1

How can you demonstrate the force on a current-carrying conductor in a magnetic field?

Answer 1

Place a current-carrying wire (e.g., a copper wire) between the poles of a horseshoe magnet.

When the current flows perpendicular to the magnetic field, the wire experiences a sideways force (it moves).
This is called the motor effect

Question 2

What is Fleming’s Left-Hand Rule?

Answer 2

It predicts the direction of the force on a conductor.

Thumb = Motion (Force)

First finger = Magnetic Field (N → S)

Second finger = Current (from + to −)
When these are at 90° to each other, the thumb points in the direction of the force on the wire.

Question 3

What happens when a current flows perpendicular to a magnetic field

Answer 3

A force is produced on the conductor, and the conductor moves in a direction perpendicular to both the current and magnetic field (as predicted by Fleming’s Left-Hand Rule).

Question 4

What factors affect the size of the force on a current-carrying conductor in a magnetic field?

Answer 4

Current (I): Greater current = stronger force

Magnetic Field Strength (B): Stronger field = stronger force

Length of Conductor (L) in the magnetic field

Angle between current and magnetic field: Maximum force when angle is 90°