Consider a large plane wall of thickness l 0.21 m, thermal conductivity k 2.5 w/m k, and surface area a 24 m2. the left side of the wall is subjected to a heat flux of 350 w/m2 while the temperature at that surface is measured to be 60 c assuming steady one-dimensional heat transfer, (a) obtain the finite difference formulation for the four nodes and b) determine the temperature of the wall by solving those equations

Line joining liquid phase with liquid and solid phase mixture is known as: a) liquidus b) solidus c) tie line d) none of the mentioned

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?

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false