A series motor runs at 1000 r. P.M. When the voltage is 415 V and the current is 30 A. The armature resistance is 0.5Ω and the series field resistance is 0.25 Ω. Determine the resistance to be connected in series to reduce the speed to 800 r. P.M with the same current.

Atank with constant volume contains 2.27 kg of a mixture of water phases (liquid-vapor). in the initial state the temperature and the quality are 127 °c and 0.6, respectively. the mixture is heated until the temperature of 160 oc is reached. illustrate the process in a t-v diagram. then, determine (1) the mass of the vapor in kg at the initial state, (2) the final pressure in kpa.