When a current-carrying conductor is placed in a magnetic field, the conductor will move
A. in a direction opposite to the lines of flux.
B. toward the more dense magnetic field.
C. toward the less dense magnetic field.
D. in the same direction as the lines of flux.
The correct answer and explanation is:
Correct Answer: B. toward the more dense magnetic field
When a current-carrying conductor is placed within a magnetic field, it experiences a force that causes it to move. This is a fundamental principle of electromagnetism and forms the basis for many electrical devices such as motors.
The interaction between the magnetic field and the current in the conductor is described by the Lorentz force. According to this law, a force is exerted on a charged particle (or a current-carrying conductor) when it moves through a magnetic field. The direction and magnitude of this force depend on the strength of the magnetic field, the amount of current, and the angle between the direction of current and the magnetic field.
This force is given by the formula F = I × L × B × sin(θ), where:
- F is the magnetic force
- I is the current in the conductor
- L is the length of the conductor in the field
- B is the magnetic field strength
- θ is the angle between the current and the magnetic field
In practical terms, the conductor tends to move toward the region where the magnetic field is stronger or more dense. This is because the force is stronger in regions of higher magnetic flux density. The denser the field lines, the greater the interaction between the field and the moving charges in the conductor, and the stronger the force that results.
This principle is applied in electric motors, where magnetic fields created by coils cause the rotor to move. The direction of motion can be predicted using the right-hand rule, where the thumb points in the direction of the current, the fingers in the direction of the magnetic field, and the palm indicates the direction of the force on the conductor.