Homework Help: physics

Posted by Rachel on Saturday, April 9, 2011 at 11:46am.

Two very long, straight, parallel wires carry currents that are directed perpendicular. Wire 1 carries a current I1 into the page (in the -z direction) and passes through the x axis at x = +a. Wire 2 passes through the x axis at x = -2a and carries an unknown current I2. The total magnetic field at the origin due to the current-carrying wires has the magnitude 2µ0I1 / ( 2πa ). The current I2 can have either of two possible values.

Find the value of I2 with the smaller magnitude, stating it in terms of I1 and giving its direction.

I have to write formula

thank you

physics - bobpursley, Saturday, April 9, 2011 at 12:37pm
Not exactly write a formula. You have to analyze the problem, then derive the formula. We don't write formulas in Physics, the Creator did that.

Here first find the distance between wires (so what is the distance between x=-2a and x=a) The force at the origin? Well it is the sum of the two forces from each wire.

Force from wire1 is kI/(2pi*distance)
http://dev.physicslab.org/Document.aspx?doctype=3&filename=Magnetism_CurrentCarryingWires.xml
The other force is similar, but the distances are different.

Now signs. Use your right hand rule, and determine the force direction for each wire. You dont know the direction for current I2, but if it is into the page, then the force subtracts from the first force.

Well, add the forces, with the +- force for the second force.

Answer this Question

Related Questions

Physics - Two long parallel wires separated by a distance, d, carry currents in ...
PHYSISC - Two parallel, straight wires that are very long are separated by a ...
Physics - Two long straight wires are perpendicular to the page and located at ...
Physics - Two long, straight, parallel wires carry current in the same direction...
Physics - (the drawing is of a square with each side equaling L and the ...
Physics - Two long, straight, parallel wires carry current in the same direction...
physics - Two parallel wires in a horizontal plane carry currents I1 and I2 to ...
Physics - The figure below shows two current carrying wires and the directions ...
physics - Two parallel wires which carry currents I1 = 69 A and I2. The top ...
Physics - Two straight and parallel wires of length 1.0 m carry a current - the ...

For Further Reading

First Name:
School Subject:
Answer: