Magnetic Force on a Current-Carrying Conductor
Describes the force exerted on a straight conductor carrying current when placed in a uniform magnetic field.
What is Magnetic Force on a Current-Carrying Conductor?
The force experienced by a charged particle or a current-carrying conductor when it moves through a magnetic field.
Key formula / rule: Magnetic Force on a Straight Current-Carrying Conductor
Key points
- To understand the origin of the magnetic force on a current-carrying conductor.
- To calculate the magnitude and direction of this force.
- To relate this force to practical applications like electric motors.
Common exam trap
Confusing the direction of the force with the direction of the magnetic field or current.
Definitions
- Term
Magnetic Force
- Meaning
The force experienced by a charged particle or a current-carrying conductor when it moves through a magnetic field.
- Term
Lorentz Force
- Meaning
The combined force exerted on a charged particle due to electric and magnetic fields. In this context, it refers to the force on moving charges within the conductor.
Learning objectives
To understand the origin of the magnetic force on a current-carrying conductor.
To calculate the magnitude and direction of this force.
To relate this force to practical applications like electric motors.
Formulae
- Name
Magnetic Force on a Straight Current-Carrying Conductor
- Note
Vector form. L is the length vector along the current.
- Expression
F = I (L × B)
- Name
Magnitude of Magnetic Force
- Note
Where θ is the angle between the direction of current (L) and the magnetic field (B).
- Expression
F = ILB sinθ
Prerequisites
Understanding of electric current.
Knowledge of magnetic fields.
Concept of Lorentz force on a moving charge.
Common mistakes
Confusing the direction of the force with the direction of the magnetic field or current.
Incorrectly applying the sine function for the angle between L and B.
Forgetting that the force is zero when the conductor is parallel to the field.
Keywords
Magnetic Force
Current-Carrying Conductor
Magnetic Field
Lorentz Force
Fleming's Left-Hand Rule
Electric Motor
Vector Cross Product
Practice preview
A straight conductor of length L carries a current I. It is placed in a uniform magnetic field B. The force experienced by the conductor is given by:…
easy
When a current-carrying conductor is placed parallel to a uniform magnetic field, the force experienced by the conductor is:…
easy
A 10 cm long wire carrying a current of 5 A is placed perpendicular to a magnetic field of 0.2 T. What is the magnitude of the force on the wire?…
medium