Select all that are true. Group of answer choices major parts of a dc motor are stator, rotor, commutator, and brushes. If the rotor of a dc motor consists of just one conductor loop, the output torque will vary in magnitude from zero to a maximum and back to zero over every half turn of the rotor. Using multiple loops in the rotor of a dc motor not only gives higher torque but also ensures a constant magnitude of the output torque. Using electromagnets in the stator of a dc motor makes higher torque values possible. In a series motor, rotor and stator are connected in series. In a shunt motor, a bypass circuit is provided to prevent overload.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Afull journal bearing has a journal diameter of 27 mm, with a unilateral tolerance of -0.028 mm. the bushing bore has a diameter of 27.028 mm and a unilateral tolerance of 0.04 mm. the l/d ratio is 0.5. the load is 1.3 kn and the journal runs at 1200 rev/min. if the average viscosity is 50 mpa-s, find the minimum film thickness, the power loss, and the side flow for the minimum clearance assembly.

Journeyman training is usually related (clo2) a)-to specific tasks b)-to cost analysis of maintenance task c)-to control process to ensure quality d)-to installation of machinery