Give the formula for finding the voltage regulation of a generator. a) % reg = {[(no-load) - (full-load)] = (no-load)} x 100 b) % reg = {[(full-load) - (no-load)] (full-load)} x 100 c) % reg = [(no-load) - (full-load)] ÷ (full-load)} x 100 d) none of the above

A d.c. series generator supplies the load of 5 kW at 250 volts. The armature resistance and series field resistances are 1 ohm and 0.5 ohm respectively. Determine the value of the induced emf.

A 1000-VA, 230/115-V transformer has been tested to determine its equivalent cir- cuit. The results of the tests are shown below. Open-circuit test (on secondary side) Short-circuit test (on primary side) Voc = 115 V Vsc = 17.1 V %3D %3D Isc 8.7 A Psc loc =0.11 A Poc = 3.9 W = 38.1 W (a) Find the equivalent circuit of this transformer referred to the low-voltage side of the transformer. (b) Find the transformer's voltage regulation at rated conditions and (1) 0.8 PF lag- ging, (2) 1.0 PF, (3) 0.8 PF leading. (c) Determine the transformer's efficiency at rated conditions and 0.8 PF lagging.

How can you tell whether a given part of the system should act as a generator or a consumer?...or as a technique?