SSC JE Electrical 2019 with solution SET-2
While estimating the overhead lines, if the number of poles required is 14, then what is the estimated number of earth sets required?
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 maximum power transfer theorem states that the DC voltage source will deliver maximum power to the variable-load resistor only when the load resistance is equal to the source resistance. Similarly, this theorem states that the AC voltage source will deliver maximum power to the variable complex load only when the load impedance is equal to the complex conjugate of the source impedance. Hence when Ri = RL the transfer of power will be maximum.
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.
The wattage rating for a ceiling fan motor is in the range of 50 to 150 W. if the ceiling Fans size ranges from 36 inches to 56 inches then the total wattage use is 55 to 100 watts.. A 48-inch ceiling fan will use 75 watts.
EXAMIANS