7.2.2 Fleming’s Left-Hand Rule HT

In this lesson, we will explore Fleming's left-hand rule, which helps determine the relative orientation of the force, current in the conductor, and magnetic field. We will also examine the factors that affect the magnitude of the force exerted on the conductor.

The Motor Effect

When a conductor carrying a current is placed in a magnetic field, the conductor and the magnet exert a force on each other. This phenomenon is known as the motor effect.

Fleming's Left-Hand Rule

Fleming's left-hand rule is a mnemonic device used to determine the relative orientation of the force, current in the conductor, and magnetic field.

According to the rule:

• The thumb represents the direction of motion or the force (F).
• The first finger represents the direction of the magnetic Field (B).
• The second finger represents the direction of the current (I).

Factors Affecting the Force

The size of the force on the conductor depends on the following factors:

• Magnetic Flux Density (B): The strength of the magnetic field influences the force exerted on the conductor.
• Current (I): The magnitude of the current flowing through the conductor affects the force experienced.
• Length (l): The length of the conductor within the magnetic field also contributes to the force.

Calculation of Force

For a conductor placed at right angles to a magnetic field and carrying a current, the force (F) can be calculated using the equation:

F = B × I × l

Variables:

• F = Force in newtons, N
• B = Magnetic flux density in tesla, T
• I = Current in amperes, A
• l = Length of the conductor in metres, m

Conclusion

Fleming's left-hand rule provides a simple and effective methodHow a writer presents perspective or viewpoint through language/structure. to determine the relative orientation of the force, current, and magnetic field in the motor effect. By using the equation F = B × I × l, we can calculate the force experienced by a conductor placed at right angles to a magnetic field and carrying a current.