School of Physics Lecture Demonstration Manual

Ea-1 Force on a Current Carrying Conductor in a Magnetic Field

Published: Tuesday 14 March 2006 - Updated: Tuesday 29 March 2011


To demonstrate that a current carrying conductor in a magnetic field experiences a force given by dF= I dl X B



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Force on Current Carrying Wire in B Field

Force on Wire Diagram


Force on a Current Carrying Wire in B Field


The aluminium strip is hung between the poles of the magnet with the aid of the two retort stands as shown. On closing the switch S1 the strip experiences a force due to the interaction between the current I and the magnetic field B.

The direction of current flow may be reversed via the rotary switch S2 to deflect the strip in the opposite direction.

Safety notes

Electrical safety 


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