To determine the direction of dot product..Fleming left hand rule is used?
Dot product is a scalar quantity.It has magnitude only and no direction.
Fleming’s left hand rule is not related to vectors.It is explained below:
Flemings Left Hand rule
Fleming’s left hand rule states that if we arrange the thumb, the middle finger, and the forefinger of the left hand at right angles to each other, then the thumb points towards the direction of the magnetic force, the middle finger gives the direction of current, and the forefinger points in the direction of magnetic field
This is shown in figure below.