Production Technology [Daily Question] Sunday, November 20, 2011

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The last edit to this post was made by Refinery Operator on 2011-11-21 06:42. Multiple-choice questions (taken from the written examination for senior-level vocational qualification assessment for compressor operators): 1. The phase sequence of three-phase AC busbars is indicated by colors, with red being used to represent ( ). Phase A, Phase B Phase B, Phase C Phase C, Phase A 2. In the following processes, which one has the lowest efficiency? A. Isothermal process B. Isobaric process C. Isochoric process D. Adiabatic process 3. In a centrifugal air compressor, an excessively large wheel diameter ratio prevents the working wheel from making full use of centrifugal force to increase the exit pressure of the gas; instead, pressure increase relies on the diffusive flow of the gas within the working wheel and the fixed components, which results in increased resistance losses and lower stage efficiency. A. Rising B. Falling C. Unchanged D. Unclear Note: 1. Please hide your reply; see how to do this at: http://bbs.hcbbs.com/thread-492556-1-1.html. 2. Do not edit after replying. 3. All participants must receive a reward. Reference answers: 1. B, 2. D, 3. B