A 230V-d. c shunt motor runs at 800r. p.m. and takes armature current of 50A. Find the resistance to be added
to the field circuit to increase speed to 1000r. p.m. at an
armature current of 80A. Assume flux proportional to
field current. Armature resistance 0.15ohms and field
winding resistance = 250ohms

Fluids at rest possess no flow energy. a)- true b)- false

Most leaks in reciprocating air compressors can be detected and minimized by: (clo4) a)-detecting leakage areas using ultrasonic acoustic detector. b)-tightening joints and connections c)-replacing faulty equipment d)-all of the given options

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?