IGCSE PHYSICS Topic : Fleming's Left Hand Rule and the Right Hand Grip Rule

The Left Hand Rule

It is well know that a current carrying conductor in a magnetic field experiences a force, and that if a conducting loop of wire moves relative to a magnetic field, a current is generated. Fleming's Left Hand Rule enables us to calculate the direction of the force in the first case and the direction of the field in the second case. This is illustrated below.

In this diagram the two fingers are horizontal at right angles and the tunmb is vertical and at right angles to both. In fact, first finger, second finger and thumb are all at right angles to each other.

The Right Hand Grip Rule

A current also produces a magnetic field. The magnetic field will loop around the conductor. We can find the sense in which it loops by gripping the conductor carrying the current in our right hand. The fingers will point in the direction of the field. This shown below to the left. We can also apply it to solenoids, in a sense, backwards. If the fingers point in the direction of the current, the thumb will point AGAINST the magnetic field.