When different types of consumers are charged at different uniform per unit rates, it is said to be Flat Rate Tariff. In this type, the consumers are grouped into different classes. Each class is charged at different uniform rate.
Simple logic of reactance diagram is that simplified equivalent circuit of power system in which the various components of power system are represented by their reactances. The reactance diagram can be obtained from impedance diagram if all the resistive components are neglected.
The neutral point of a generator is usually earthed to facilitate protection of the stator winding and associated system. Earthing also prevents damaging transient overvoltages in the event of an arcing earth fault or ferro resonance. For HV generators, impedance is usually inserted in the stator earthing connection to limit the magnitude of earth fault current.
Equivalent resistance of the circuit, Req = (12||18) + 8 Req = 7.2 + 8 Req = 15.2 ohm Source current = current through 8 ohm resistor, I = Vr/R8 I = 20/8 I = 2.5 A Supply votage V = I*Req V = 2.5*15.2 V = 38 V