No Electromagnetic Force in Moving Magnet & Solenoid

[Dale]

if we have a solenoid suspended freely and no current is traversing it, and we approach a magnet toward it, would it repel or rotate?

That is a good question, I guess it would depend on the exact geometry, but I don't know for sure.

can we consider a solenoid totally as a bar magnet when a current traverses it??

The magnetic field of a solenoid is very similar in shape to the magnetic field of a bar magnet, but I don't know what you mean by "totally".

my another question is: when we are providing a wire, u r considering that we are providing current, this is confusing me there is a wide difference between a wire and a current?

Yes, there is a wide difference between a wire and a current. However, in all of your examples so far you have a changing flux in a circuit and therefore an emf and therefore a current in the wire. If you made a different example then I would answer differently, but so far you have only made examples of wires with currents.

 

[brainyman89]

You provided B and a means of determining I (wire/resistor geometry and composition) using Maxwell's equations. From B and I you obtain f. You provided both B and I, although the I is hidden:

Did u mean in this statement that providing variable B equals providing B and I (i.e variation=current), hence i will get B and I thus producing F.

 

[Dale]

Did u mean in this statement that providing variable B equals providing B and I (i.e variation=current), hence i will get B and I thus producing F.

Essentially, but I would have said "providing variable B and wire/resistor geometry equals providing B and I".