Question

Two long parallel wires placed side-by-side on a horizontal table carry identical size currents in opposite directions. The wire on your right carries current toward you, and the wire on your left carries current away from you. From your point of view, the magnetic field at the point exactly midway between the two wires

A) points away from you.
B) is zero.
C) points toward you.
D) points down.
E) points up.

Answer 1

D) points down.

Step-by-step explanation:

The problem can be solved by using the right-hand rule to determine the direction of the magnetic field produced by each wire:

- Thumb: direction of the current in the wire

- The other fingers wrapped around the wire: direction of the magnetic field

So let's apply this rule to both wires:

- Wire on the right:

-- Thumb: direction of current --> toward you

-- Other fingers: direction of magnetic field --> point down (at a point on the left of the wire, which is where we want to determine the total field)

- Wire on the left:

-- Thumb: direction of current -->away from you

-- Other fingers: direction of magnetic field --> point down (at a point on the right of the wire, which is where we want to determine the total field)

So, at the point exactly midway between the two wires, both magnetic fields point down, so when they add together the total field will also point down.