A 4-pole, 50 Hz, slip ring induction motor has rotor resistance and standstill reactance referred to stator of 0.2 ohm and 1 ohm per phase respectively. At full load it runs at 1440 rpm. Determine the value of resistance to be inserted in rotor in ohms per phase to operate at a speed of 1200 rpm, if (a) the load torque remains constant, (b) the load torque varies as the square of the speed. Neglect stator resistance and leakage reactance. Assume a ratio of stator to rotor turns of 1.1.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false

Afluid flows with a velocity field given by v=(x/t)i.. determine the local and convective accelerations when x=3 and t=1.