Apparent Power (S): It is defined as the product of r.m.s value of voltage (V) and current (1). It is denoted by S.
S = V/I Volt Ampere
Voltage Scale Span of instrument = Vmax − Vmin
Vmax = 5 V
Vmin = −5V
Span = 5 −(−5) = 10 V
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
A P-N junction acts as a voltage-controlled switch. During forward biasied the p-n junction diode acts like an ON switch. When reverse biased, it acts like an OFF switch.
The slow but continuous rotation of the energy meter (Induction type) when only the pressure coil is excited and no current is flowing through the current coil is called creeping. This error may be due to excessive friction compensation, excessive voltage supply, stray magnetic field, etc.
In order to prevent creeping at no-load, two holes of the same radius are drilled in the disc on the opposite side of the spindle.