Three single-phase, 10 kVA, 2400/280 V, 60-Hz transformers are connected to form a three-phase, 2400/480 V transformer The equivalent impedance of each single-phase transformer referred to the primary side is 10 + j30 Ω. The transformer bank delivers 30 kVA at 480 V and 0.9 power factor lagging.
a. Draw the three-phase schematic diagram showing the transformer connection. Draw a per-phase equivalent circuit.
b. Determine the primary current and power factor.
c. Determine the primary voltage.
d. Determine the voltage regulation.

Apiston-cylinder with a volume of 0.25 m3 holds 1 kg of air (r 0.287 k/kgk) at a temperature of 100 c. heat transfer to the cylinder causes an isothermal expansion of the piston until the volume triples. how much heat is added to the piston-cylinder?

Apump is used to circulate hot water in a home heating system. water enters the well-insulated pump operating at steady state at a rate of 0.42 gal/min. the inlet pressure and temperature are 14.7 lbf/in.2, and 180°f, respectively; at the exit the pressure is 60 lbf/in.2 the pump requires 1/15 hp of power input. water can be modeled as an incompressible substance with constant density of 60.58 lb/ft3 and constant specific heat of 1 btu/lb or. neglecting kinetic and potential energy effects, determine the temperature change, in °r, as the water flows through the pump.

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false