Helium undergoes a cycle. The initial Pressure is 100kPa and initial volume is 0.4m3 . Process1-2: Polytrophic compression with n=1.3 until the volume is half of the initial volume Process2-3: Isobaric compression Process 3-1: Isochoric process Show the cycle on a P-v diagram and find the net work of the cycle.

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?

Water in a partially filled large tank is to be supplied to the roof top, which is 8 m above the water level in the tank, through a 2.2-cm-internal-diameter pipe by maintaining a constant air pressure of 300 kpa (gage) in the tank. if the head loss in the piping is 2 m of water, determine the discharge rate of the supply of water to the roof top in liters per second.

Which from the following instrument is commonly used to detect the high pitch butzing sound in bearings? [clo4] a)-digital ultrasonic meter b)-infrared camera c)-spectroscopic d)-vibrometer