A fixed horizontal wire carries 200A current below which another wire of linear density 10gm/m carrying current is kept at a depth 2cm & parallel to the first wire. If the 2nd wire hangs in air find the current in it. If the current in the 1st wire increases by 220A, what will be the instantaneous acceleration on the 2nd wire.

Asked by padmakrith | 17th Jun, 2013, 11:16: AM

Expert Answer:

force on a unit length of wire due to the above wire, F = BI
where I is the current in the wire
B is the magnetic field due to the wire above
let r be the distance between the two wires
B = ?(200)/(2?r)
and force due to weight = mg = 10g/1000
 
thus comparing thw two, we can calculate the current in the lower wire I
 
Now, force when current in above wire is 220A , F' = ?(200)/(2?r) I
net force = F' - mg
and we can find the net acceleration on the wire.

Answered by  | 17th Jun, 2013, 01:00: PM

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