The resistivity of iron at 20°C is 9.71 × 108 The resistivity of silver at 20°C is 1.59 × 108 The resistivity of Glass at 20°C is 1.10 × 109 The resistivity of nichrome at 20°C is 100 × 108 Hence silver is the least resistive material in the given option.
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
Form factor: The ratio of r.m.s (or effective) value to average value is the form factor (Kf) of the Waveform. It has used in voltage generation and instrument correction factors. Peak factor: The ratio of maximum value to the r.m.s value is the peak factor (Kp) of the waveform. Form Factor × Peak Factor = (RMS Value / Average Value) * (Maximum Value / RMS Value) = Maximum Value / Average Value
A phase sequence is an order or sequence in which the currents or voltages of different phases attain their maximum values. In a three-phase system, there are only two possible phase sequences: R-Y-B (positive Phase Sequence) and R-B-Y (Negative Phase Sequence).