In this lab we will place a wire between the poles of a magn

In this lab. we will place a wire between the poles of a magnet and investigate the magnetic force on the wire. We will measure the force on the wire indirectly - by placing the magnet on a scale, and measuring the scale reading with current off, then current on. Explain why we can say anything about the force on the wire by only measuring effects on the magnet. (this is a Physics 211 question.)

Solution

The force on current carrying wire is,

F= ILBsin(Theta)

Here B is the magnetic field and theta is the angle between the wire and the magnetic field.

So, force on the wire carrying current is dependent on the magnetic field direction and direction of the particles.When motion of the particle is parallel to direction of the magnetic field, force acting on the wire is zero.

When the motion of the particle is perpendicular to the direction of the magnetic field, force perpendicular to its current direction.

Thus, force acting on the wire is measured only by the effects on the magnet.