TRANSFORMERS Find the all-day efficiency of a transformer having maximum efficiency of 98.5 per cent at 20 KVA at unity power factor and loaded as follows 11 hours: 5 kW at 0 7 power factor lagging 6 hours: 8 kW at 0.8 power factor lagging 7 hours: no load The maximum efficiency of the transformer occurs at 80 per cent of full load.​

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.