Form factor: The ratio of r.m.s (or effective) value to average value is the form factor (Kf) of the Waveform. It has used in voltage generation and instrument correction factors. Peak factor: The ratio of maximum value to the r.m.s value is the peak factor (Kp) of the waveform. Form Factor × Peak Factor = (RMS Value / Average Value) * (Maximum Value / RMS Value) = Maximum Value / Average Value
The permeance of the magnetic circuit is defined as the reciprocal of the reluctance. Permeance = 1/Reluctance It is defined as the property of the magnetic circuit due to which it allows the flow of the magnetic flux through it. Permeance is analogous to conductance in an electric circuit.
While estimating the overhead lines, the first and last pole is always earth connected and after every 3rd electrical pole, the fourth pole is earthed. Therefore, the approximate number of required ground set = 4
The commutator is a feature of d.c.motors. But a.c. motors having wound rotor with brushes and commutator arrangements, are called commutator motors that work on single-phase a.c. supply. The commutator arrangement present in these motors is similar to the armature of a d.c. motor.E.g. of single-phase commutator type induction motor is Repulsion Motor Repulsion-Induction Motor AC Series Motor Universal Motor