Lap Winding:-In a lap winding the number of parallel paths (a) is always equal to the number of poles (p) and also to the number of brushes. In the given question number of poles is 4 hence the number of brushes will be 4. Wave Winding:- In wave windings, the number of parallel paths (a) is always two and there may be two or more brush positions.
We use universal motors in mixer grinders. Universal motors can run both on a.c. and d.c. The universal motor works on the same principle that DC series motor works. DC series motor has the characteristics of operating at high-speed when there is no load and operating at low-speed when the load is applied. It has high starting torque characteristics. So it is used in mixers, where initially we put some load at starting.
The melting point of Eureka is 1221 to 1300 °C The melting point of Kanthal is 1,425 °C The melting point of Nichrome is 1400 °C The melting point of Graphite is 3,600°C Hence Eureka has the least range of temperature.
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.
EXAMIANS
