A symmetrical $$400V,$$ $$3$$-$$\phi $$ supply is connected to the network shown in fig. The phase sequence is $$RYB.$$ Find the reading on the wattmeter

$${R_1} = 30\Omega ,\,\,{X_1} = 50\Omega ,\,\,$$ and $${X_2} = 40\Omega $$

A $$DC$$ shunt generator delivers $$60$$ $$KW$$ at $$240$$ $$V$$ and $$360$$ $$rpm.$$ The armature and field resistances are $$0.015\,\,\,\Omega $$ and $$60\,\,\,\Omega $$ respectively. Calculate the speed of the machine running as a shunt motor and taking $$60$$ $$KW$$ input at $$240$$ $$V.$$ Allow $$1$$ volt per brush for contact drop.

In a $$50$$ $$KVA,$$ $$11$$ $$KV/400$$ $$V$$ transformers, the iron and copper losses are $$500$$ $$W$$ and $$600$$ $$W$$ respectively under rated conditions. Calculate the efficiency on unity power factor at full load. Find the load for maximum efficiency and the iron and copper losses corresponding to this load.

A synchronous generator connected to an infinite bus is overexcited. Considering only the reactive power, from the point of view of the system, the machine acts as