# Conditions needed for magnetic force on a conductor

• Tane
In summary, a conductor needs to be carrying electric current in order to experience a force from a magnetic field, with the exception of a moving wire with static charge. A conductive element, such as a copper specimen, takes longer to fall when experiencing the magnetic field of a solenoid due to the magnetic force pushing against the inside of the solenoid and causing deceleration. This can occur even without initial current being carried by the copper. This can be explained by Lenz's law, which states that a straight conductor moving perpendicular to a fixed magnetic field generates its own current and experiences a force opposing its original motion.
Tane
Homework Statement
Hello,

First question, does a conductor need to be carrying electric current, in order to experience a force from a magnetic field acting on it?

Secondly, why does a conductive element (e.g. a copper specimen) take longer to fall, when experiencing the magnetic field of the solenoid that it is falling through. Is the copper experiencing magnetic force and pressing against inside of solenoid, causing deceleration due to friction? How can this be if there is no initial current carried by copper?

Please assist me with understanding these scenarios, it would be much appreciated.
Thanks.
Relevant Equations
F = iLB sin(theta)
F = qvB
V=iR (possibly)
none

Tane said:
Problem Statement: Hello,

First question, does a conductor need to be carrying electric current, in order to experience a force from a magnetic field acting on it?
Yes. Only exception I can think of is with a moving wire with static charge on it.
Secondly, why does a conductive element (e.g. a copper specimen) take longer to fall, when experiencing the magnetic field of the solenoid that it is falling through. Is the copper experiencing magnetic force and pressing against inside of solenoid, causing deceleration due to friction? How can this be if there is no initial current carried by copper?
I can't think of any impeding force if a copper element falls thru a tube with B field parallel to the falling direction, as is the case with your solenoid. Even if the element carried net charge.

A straight conducter moving perpendicular to a fixed magnetic field generates its own current (movement of charge) which then causes a force opposìng the original motion. This is essentially Lenz's law and - in one way or another - explains slowing of a charge carrier (e.g. copper coin) moving in a magnetic field.

## What is the definition of magnetic force on a conductor?

Magnetic force on a conductor is the force exerted on a current-carrying conductor placed in a magnetic field. This force is perpendicular to both the direction of the current and the direction of the magnetic field.

## What are the necessary conditions for magnetic force on a conductor?

The necessary conditions for magnetic force on a conductor are a current-carrying conductor and a magnetic field. Both of these must be present in order for the force to be exerted on the conductor.

## How does the direction of the magnetic field affect the force on a conductor?

The direction of the magnetic field determines the direction of the force on a conductor. If the magnetic field is perpendicular to the current, the force will be in a different direction than if the magnetic field is parallel to the current.

## Can magnetic force be exerted on a non-current-carrying conductor?

No, magnetic force can only be exerted on a current-carrying conductor. This is because the force is created by the interaction between the magnetic field and the moving charges in the conductor.

## How is the strength of the magnetic force on a conductor determined?

The strength of the magnetic force on a conductor is determined by the magnitude of the current, the strength of the magnetic field, and the angle between the direction of the current and the direction of the magnetic field. The greater these values are, the stronger the force will be.

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