I\'ve watched this video on YouTube by Sixty Symbols entitled \"Currents and Mag

Question

I've watched this video on YouTube by Sixty Symbols entitled "Currents and Magnets". In the video, the professor demonstrates the expansion of a wire due to current heating it up and he also demonstrates how the current interacts with a magnet. I want to ask about the magnetic interaction.

At about 2:28 he shows how the orientation of the magnet relative to the wire/current determines whether the wire is repelled or attracted. It appears that, mathematically, whether the wire is pulled or pushed is determined by the cross product between the vector of the flow of the current, c? , and the vector of the magnetic field, m? .

However, the cross product is not commutative (order of the operands is important). What determines whether I should cross c? with m? or whether I cross them the other way around?

Explanation / Answer

There is an expression for the Lorentz force on a charge in a magnetic field. This expression is based on experimental facts, and the order in the vector product of the charge velocity and the magnetic field is fixed.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.