A DC motor can be operated from a single-phase AC supply. The direction of the torque produced by a DC machine is determined by the direction of current flow in the armature conductors and by the polarity of the field. Torque is developed in a DC machine because the commutator arrangement permits the field and armature currents to remain in phase, thus producing torque in a constant direction. A similar result can be obtained by using an AC supply, and by connecting the armature and field windings in series.
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 stroboscopic effect is a visual phenomenon that happens when a blinking light source glows an object in movement, generating a sequence of samples. The stroboscopic effect is based on Illuminance hence it is not related to the transmission and distribution of electric power.
The size of the conduit is 62 meters. In conduit, there is a 2-phase wire and 1 neutral wire. Therefore the total number of conducting wire is 3 in a conduit Total length of cable = 62 × 3 = 186 meters.
EXAMIANS
