Sketch root locus plots for the following open-loop transfer functions. You must explain how you got your sketches. Based on your plots in each case, state whether an increase in gain causes closed-loop instability, a decrease in gain causes closed-loop instability, the closed-loop system is stable for any positive gain value, and justify your reasoning.

(a) G(s) = (s+1)/(s(s-2))
(b) G(s) = (s-1)/((s+2)(s²+2s+5))
(c) G(s) = (s+0.5)/(s(s+1)(s-1))

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?

Machinery that is a key part of the process and without which the plant or process cannot function is classifed as: (clo4) a)-critical machinery b)-essential machinery c)-general purpose machinery d)-none of the specified options.

Air is compressed isentropically from an initial state of 300 k and 101 kpa to a final temperature of 1000 k. determine the final pressure using the following approaches: (a) approximate analysis (using properties at the average temperature) (b) exact analysis