Electricity & Megnetism

# Magnetic force in a straight conductor

Wire placed in a magnetic field: a force of magnetic characteristic acts on it.

When electric charges move inside a wire conducting electricity, we say that there is an electric current, and the representation of this current is given by the letter i .
When we place a certain wire carried by an electric current inside a magnetic field, it is verified that it suffers the action of a force, which we call magnetic force, represented by the letter F .

In a straight conductor carried by an electric current of intensity i , each of the charges, which move with a speed v, is subject to the action of a magnetic force whose intensity is F and is given by the equation:

F = │q│.vBsenӨ

Where is the angle formed between the speed of the charge and the magnetic field.

For a straight conductor of length l, traversed by a current i, we have:

l = v.Δt and i = q/Δt l = vq/i qv = li

Where:

l – length of the wire; v – load speed; q – electrical charge; Δt – time variation; B – magnetic field; i – electric current.

Substituting qv = li into the equation F = │q│.vBsenӨ, we have:

F = BilsenӨ