Ampere works law or Circuital Law This law relates to work done in a magnetic circuit i.e. closed magnetic flux path. The work done on or by a unit N-pole in moving once round any complete path is equal to the product of current and number of turns enclosed by that path
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
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.
Average speed:- The distance covered between two stops divided by the actual time of the run is known as average speed. Average speed = (Distance between stops)/(Actual time of run) Schedule speed:- It is defined as the ratio of distance covered between two stops and the total time of run including the time of the stop. Schedule speed = (Distance between stops) /(Actual time of run + Stop time) This shows that schedule speed is always smaller than the average speed. The difference is large in the case of urban and suburban services and is negligibly small in the case of main-line service.
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.
Indian Electricity Rules specify that the maximum load on a light/fan sub-circuit should not exceed 800 watts and the number of points should be limited to 10. Hence for light load number of sub-circuit = 3000/800 = 3.75 = 4 Indian Electricity Rules specify that the maximum load on a power sub-circuit should not exceed 3000 watts and the number of outlets should be limited to two. For the power sub-circuit load number of sub-circuit = 6000/3000 = 2 Total subcircuit = 4 + 2 = 6