Magnetic Field Strength (H) gives the quantitative measure of strongness or weakness of the magnetic field. H = B/μo Where B = Magnetic Flux Density μo = Vacuum Permeability Magnetic field due to infinite Linear current-carrying conductor is B = μoI/2πr B/μo = I/2πr H = (I/2πr)A/m
The centrifugal switch is used to disconnect the starting winding of the motor once the motor approaches its normal operating speed i.e 50% – 70% speed.
When two solid surfaces are brought into contact, a finite normal force is needed to pull the two solids apart. This force is known as the force of adhesion or simply adhesion. The coefficient of adhesion () defined as the ratio of tractive effort required to propel the wheel of a locomotive to its adhesive weight. Adhesion traction is the friction between the drive wheels and the steel rail. µ = Ft/W Where Ft = Tractive effort W = Adhesive Weight
Galvanized steel conductors do not corrode, and possess high resistance. Hence such Wires are used in telecommunications circuits, earth wires, guard wire, stray wire, etc.