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0 votes
3 answers
624 views

Deflection of compass and rest position through Magnetic induction

I found a problem with a compass and a magnet, as diagrammed below. The needle of the compass was oscillating in an uniform magnetic field, but when a soft iron bar was placed near the needle, then ...
0 votes
3 answers
5k views

Magnetic flux through current loop

I am trying to calculate the total magnetic flux through the surface of a current loop. I feel that this flux should be finite and nonzero -- so far any attempt in calculating failed. Can this really ...
2 votes
1 answer
878 views

Why should there be an induced electric field if magnetic field is constant? [closed]

Problem statement: The curved surface of a very long hollow non conducting cylinder of radius $R$ is uniformly charged with surface charge density $\sigma$. A non conducting small circular ring of ...
1 vote
3 answers
1k views

Why is the curl of magnetic field $0$ outside the conductor and non-zero inside? [duplicate]

I dont understand why the magnetic field does not curl outside the cable, according to this example, since I would expect the magnetic field lines to go back on themselves around the cable like shown ...
0 votes
1 answer
77 views

Confusion regarding torque given by M×B

The magnetic torque acting on a loop of magnetic moment M placed in a magnetic field B, is given by τ=M×B. My question is, about which axis does this give the torque about? Is it the instantaneous ...
0 votes
1 answer
856 views

Induced current in a circular loop [closed]

In this question I tried using right hand thumb rule for long wire to get magnetic field into plane of paper which induces clockwise current in Loop,again by thumb rule. The problem arises when force ...