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If the length of current carrying conductor increases, what is the effect on the force?
increases
decreases
remain the same
become zero
increases
The Lorentz force experienced by a current-carrying conductor placed in a magnetic field is directly proportional to its effective length. As the length of the conductor exposed to the magnetic field increases, the number of charges moving within the field increases, thereby increasing the total force.
The Lorentz force experienced by a current-carrying conductor placed in a magnetic field is directly proportional to its effective length. As the length of the conductor exposed to the magnetic field increases, the number of charges moving within the field increases, thereby increasing the total force.
F=BIlsin(╬╕) тАФ Magnitude of magnetic force on a current-carrying conductor
FтИЭl тАФ Relationship showing direct proportionality between force and length
According to the motor principle, the magnetic force F is given by the cross product of the current element and the magnetic flux density. Since the conductor is usually perpendicular to the magnetic field, the magnitude of the force is calculated as F=BIlsin(╬╕). Because FтИЭl, an increase in length l while maintaining constant magnetic flux density B and current I results in a linear increase in the total force experienced.
The force is perpendicular to both the direction of the current and the magnetic field lines.
The maximum force is achieved when the conductor is oriented perpendicular (90┬░) to the magnetic field lines.
The force magnitude depends on the flux density (B), current (I), and active length (l).
Higher output torque in motors with longer armature conductors.
Scalability in electromagnetic devices.
Increased conductor length leads to higher internal resistance.
Potential for increased ohmic (I┬▓R) losses.
DC motors and generators
Electromagnetic actuators
Loudspeakers and voice coils
The SI unit of force is the Newton (N).
Option B, C, and D are incorrect because they contradict the direct proportional relationship defined by the Lorentz force law.
A is correct тАФ The magnetic force is directly proportional to the length of the conductor; therefore, increasing the length increases the force.
Always remember the Fleming's Left-Hand Rule for motors to determine the direction of force, as direction and magnitude are both critical for electromechanical design.