In what type of application would a permanent magnet dc motor be highly suitable? (select all that apply) 1. you need a linear torque-speed curve 2. you need relatively high energy efficiency in a dc motor 3. you need to run the dc motor at speeds over 4000 rpm 4. you have very little space with which to package the dc motor 5. you need a very low cost dc motor, preferably $3 or less.

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false

An ideal otto cycle with air as the working fluid has a compression ratio of 8. the minimum and maximum temperatures in the cycle are 300 k and 1340 k. use constant specific heats at room temperature to determine (a) the amount of heat transferred to the air during the heat- addition kj/kg, (b) the thermal efficiency, and (c) the thermal efficiency of a carnot cycle ope limits. process, in rating between the same temperature