A Rectangle Parallel to a Magnetic Field

[aximwolf]

Homework Statement

file:///Users/LabGuest/Desktop/CH26.tiff

Homework Equations

F_B= qv cross B

The Attempt at a Solution

If the the rectangle is parallel to the magnetic field and we know that F_B is perpendicular to the B field itself than there should be a net Torque but no net force. Is this assumption correct?

My first intuition was to say there was a net force and no net torque but I think that is wrong because magnetic force acts perpendicular to the magnetic field (B).

 

[ehild]

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The Attempt at a Solution

If the the rectangle is parallel to the magnetic field and we know that F_B is perpendicular to the B field itself than there should be a net Torque but no net force. Is this assumption correct?

Yes, it is correct. Can you explain, why?

ehild

 

[aximwolf]

Yes because Magnetic Force = qv cross B thus it acts perpendicular to the magnetic field (B) since it is a cross product. The magnitude of the force is qvbsin(theta).

 

[ehild]

But then there can be a net force on the rectangle, perpendicular to it, is it right?

What is v in the formula?

ehild

 

[cupid.callin]

there is a different formula (derived from the formula u wrote) used in case of currents ... do you know it?

 

[WatermelonPig]

I would consider the magnetic force on each segment of the loop and sum these.

 

[cupid.callin]

I would consider the magnetic force on each segment of the loop and sum these.

correct way !