ROTOR FREQUENCY

Induction Motor Speed of Stator magnetic field = Ns Speed of rotor = Nr Slip, S = (Ns-Nr) / Nr As the stator magnetic field rotates at Ns and the rotor rotates at Nr in the same direction the relative speed of magnetic field with respect to conductor is Ns-Nr In case of Induction motor […]

MAGNETIC MATERIAL

Diamagnetic Material The materials that allow flow of magnetic field through them are called as Magnetic Materials. In Diamagnetic material there is no magnetism in the absence of external magnetic field. (Shown in fig. 1) When magnetic field is applied dipoles are induced and they orient in a direction opposite to external magnetic field. (As […]

ELECTRICAL MATERIALS

Conducting Material (Cu vs Al) •Electrically Conducting Material :- This materials carry current in an electrical machine. •Highly Conducting Material :- Copper, Aluminum, Gold, Silver. •Highly resistive material:- Alloys (heating elements)             Now,    R=Ro(1+αΔT) Where α= temperature coefficient of resistance ΔT= Change in temperature of per degree Celsius ΔT= Change in temperature of per degree […]

TRANSFORMER

A transformer (Fig. (A)) is a static device that consists of two or more stationary electric circuits interlinked by a common magnetic circuit to transfer electric energy between them. The transfer of energy from one circuit to another takes place without a change in frequency. What are Step-up and Step-down Transformers? This is a very […]