The rectangular wire of the image is placed on yz plane and is immersed in a magnetic field which magnitude and direction is :

$$\vec B = \frac{0.05}{\sqrt{2}}(\hat i + \hat j)$$

a) Compute the magnetic dipole moment and torque over the wire when the current going through is 5A

b) Compute the magnetic dipole moment and torque over the wire when it turns counterclockwise 45 degrees respect to z axis and the current is also 5A

My try:

a) Pretty confident with it.

b) I have been thinking about 'counterclockwise 45 degrees with respect to z axis means that you look along the +z direction from the origin. The plane of the loop then lies along the $-(\hat{i}+\hat{j})$ direction so μ and B are perpendicular. Torque is now a maximum' and I do not have a clear idea yet. I think we are in a situation liken to the one depicted here:

But here as you can see μ (normal vector) and B are not perpendicular. Could you explain this with more detail?

Thank you

See similar questions : [magnetic moment of the loop](http://physics.qandaexchange.com/?qa=1880/) and [calculating magnetic moment and current induced](http://physics.qandaexchange.com/?qa=2039/)

edited Aug 2, 2018 by sammy gerbil