EX2: An interconnected 60 Hz power system consists of one area with three turbine-generator units rated 1000, 750 and
500 MVA respectively. The regulation constant of each unit is R = 0.05 pu
based on its own rating. Each unit is initially operating at one half of
its own rating, when the system load suddenly increase by
200 MW. Determine (a) the per unit area frequency
response characteristic (B) on 1000 MVA system base. (b)
the steady state drop in area frequency and ( C ) the
increase in turbine mechanical power output of each unit.
Assume APref of each turbine generator remain constant.
Neglect losses and the dependence of load on frequency.

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.

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2