Working Principle of D.C Motor

A) An electric motor is a machine which changes electrical energy into mechanical energy.

B) When a current carrying conductor is placed in a magnetic field, it experience a mechanical force whose way is given by " Flemings Left hand rule" & magnitude is given by F= B.I.L Newton

C) When field magnets are excited and armature conductors are supplied with current from supply main, they experience a force tending to move the armature. Armature conductors under N-Pole are supposed to carry current in (crosses) and those under S-Pole to carry current out (dots).