The following test data were taken on a 5.5 kw, four-pole, 220-v, 50-hz, y-connected im having a rated current of 28 a. dc test: vdc = 13.6 v idc = 28.0 a no-load test: vl = 208 v f = 50 hz i = 8.17 a pin = 420 w locked-rotor test: vl = 25 v f = 15 hz i = 27.9 a pin = 920 w (a) determine the per-phase equivalent circuit of this motor. 4 marks (b) if the motor runs at 1425 rpm, calculate the input current drawn using the equivalent circuit parameters. 4 marks (c) solve the equivalent circuit and plot power input, input current, power output, toque, power factor as a function of speed (slip). draw the torque versus speed characteristics of the motor.

A-mn has a cubic structure with a0 0.8931 nm and a density of 7.47 g/cm3. b-mn has a different cubic structure, with a0 0.6326 nm and a density of 7.26 g/cm3. the atomic weight of manganese is 54.938 g/mol and the atomic radius is 0.112 nm. determine the percent volume change that would occur if a-mn transforms to b-mn.

The short distance from the objective lens to the object causes problems at high magnification. which of the following is the most serious? a. cleaning the object surface b. positioning the object c. reflection from the object surface. d. illumination of the object

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w