I NEED IMMEDIATE HELP for solving the magnitude and direction of current

[Bk8907]

ok here's the prob.

Two parallel wires are 20cm apart. EAch wire is 1.5 m long. The wire on the left carries 10 A of current up. Find the magnitude and direction of the current of the wire on the right ir it is REPELLED WITH A FORCE OF 10N.

please help

 

[.ultimate]

Appy Felmmings left hand rule

 

[Bk8907]

LEFT hand? I thought there was only RIGHT hand

 

[Ki Man]

just for future reference, this was posted in the wrong section

http://en.wikipedia.org/wiki/Right-hand_rule scroll down

 

[.ultimate]

Strech Left hand's First finger, forefinger n thumb

First Finger - direction of magnetic field
Middle Finger - Direction of current
Thumb - direction of force on the conductor/wire

Right hand is for Electromagnetic Induction EMI

Magnitude can be calculated by F=B.I.L (or BqV in case or a moving charged partile)

 

[Bk8907]

what? wrong section?

 

[NeoDevin]

Questions like this belong in the homework help section.

 

[Bk8907]

ok, so from my problem, the current on the second wire is up (north) and what does B stand for again?

 

[Bk8907]

oh ok neo devin

 

[.ultimate]

Addendum - Apply Right hand thumb rule to find direction of magnetic field around the wire carrying current where thumb is for direction of current and curled fingers are for magnetic filed( this is different from motor and dyanmo rule)

 

[Bk8907]

so the current on the second wire IS north, but now with the 10N repulsion, how do i find magnitude?

 

[.ultimate]

B is magnitude of the magnetic filed


B= \frac {u_0.I}{2 \pi r}

u_0 permeability of vacuum

(Dont have enough knowledge to assist in this context, sorry)

 

[Bk8907]

wow what a formula! i use F=2K'I/r