# How Does a Magnetic Field Affect a Wire Carrying Current?

• Physics345
In summary, a wire with a current of 2.0 A [W] and a magnetic field of 1.4 T [N] experiences a magnetic force of 11N [down] when it crosses the field. If the wire is rotated in the horizontal plane, the force will decrease and the angle will change. If the current is doubled, the force will double and the current will move twice as fast. If the magnetic field is reversed, the direction of the magnetic force will reverse.
Physics345

## Homework Statement

A magnetic field of 1.4 T [N] is 4.0 m wide. A very long wire crosses the field.

a) If the current in the wire is 2.0 A [W], find the magnetic force on the wire.

b) What will happen to the force on the wire if
i) The wire is rotated slightly in the horizontal plane?
ii) The current is doubled?
iii) The magnetic field is reversed?

F_m=ILB

## The Attempt at a Solution

a)

a) F_m=ILB
F_m=(-2.0)(4.0)(1.4) F_m=-11.2N=11N
F_m=11N [down]
Therefore the magnetic force on the wire is 11N [down]

b)

i) Since the wire is no longer in a 90 degree angle the magnetic force will decrease and the angle will change

ii) The magnetic force will double and the current will move twice as fast.

iii) The direction of the force will reverse.

Last edited:
Hi there,
I think you are OK with a and b, but not c. The magnetic field is not what is producing the current. The current is produced by a battery, or something, outside of the magnetic field.

Thanks,
Gene

Physics345
Hi there,
I think you are OK with a and b, but not c. The magnetic field is not what is producing the current. The current is produced by a battery, or something, outside of the magnetic field.

Thanks,
Gene

What are you referring to when you say c?
If you are referring to 2. iii), then good call I just noticed that is wrong it should be: The direction of the magnetic force will reverse

## 1. What is a magnetic field?

A magnetic field is a region in space where a magnet or electric current can exert a force on other objects. It is represented by invisible lines of force that point from the north pole to the south pole of a magnet.

## 2. How does a magnetic field affect a wire?

A magnetic field can induce an electric current in a wire that is moving through the field or is placed perpendicular to the field. This is known as electromagnetic induction and is the basis for many technologies, such as generators and electric motors.

## 3. How is a magnetic field created by a wire?

When an electric current flows through a wire, it creates a circular magnetic field around the wire. The strength of the magnetic field depends on the amount of current flowing through the wire.

## 4. What is the right-hand rule for magnetic fields?

The right-hand rule is a method for determining the direction of the magnetic field around a wire. If you point your right thumb in the direction of the current, the fingers of your right hand will curl in the direction of the magnetic field.

## 5. How can a magnetic field be strengthened?

A magnetic field can be strengthened by increasing the amount of current flowing through a wire or by coiling the wire to create multiple loops. Additionally, placing a ferromagnetic material, such as iron, in the vicinity of the wire can also increase the strength of the magnetic field.

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