What is the formula for calculating the magnitude of the mechanical force experienced by a current-carrying conductor perpendicular to the magnetic field, where B = magnetic flux density, I = Current and L = Length of the conductor?

Concept

The mechanical force experienced by a current-carrying conductor placed in a magnetic field is given by Fleming's left-hand Rule.

Fleming’s Left-hand rule states that if the thumb, forefinger, and middle finger of the left hand are stretched into mutually perpendicular directions such that the index finger and middle finger of a stretched left hand direct the magnetic field and electric current respectively then the thumb shows the direction of motion or force acting on the conductor.

The magnitude of the force is given by:

F = B × I × L

where, B = Magnetic flux density

I = Current 

L = Length of the conductor

Additional Information 
Fleming's Right Hand Rule

Fleming’s Right-hand rule states that if we arrange our thumb, forefinger, and middle finger of the right-hand perpendicular to each other, then the thumb points toward the direction of the motion of the conductor relative to the magnetic field, the forefinger points toward the direction of the magnetic field and the middle finger points towards the direction of the induced current.