A long piece of wire with a mass of 0.1kg and a total length of 4m is used to make a square coil with a side of 0.1m. The coil is hinged along a horizontal side, carries a 3.4A current, and is placed in a vertical magnetic field with a magnitude of 0.01T.(adsbygoogle = window.adsbygoogle || []).push({});

a) Determine the angle that the plane of the coil makes with the vertical when the coil is in equilibrium.

For this part I was thinking, mg = F = BILcos phi, where phi is the angle with respect to the vertical...

phi = arccos (mg/BIL)

Now, I thought, "Which L can I use?" and I couldn't find the answer using different values.. can anyone please show me where I went wrong?

b) Find the torque acting on t he coil due to the magnetic force at equilibrium.

I'm guessing a) will give me what I need for this part.

The answers are:

a) 3.97deg

b) 3.39 x 10^-3 Nm

Thanks for any pointers!

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# Homework Help: Magnetics question!

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