The two parallel inductors are connected across the terminals of a black box at t = 0. The resulting voltage v(t) for t ≥ 0 is known to be 40e-1.25t V. a. Replace the original inductors with an equivalent inductor and find i(t) for t ≥ 0. b. Find i1(t) for t ≥ 0. c. Find i2(t) for t ≥ 0. d. How much energy is delivered to the black box in the time interval 0 ≤ t ≤ [infinity]? e. How much energy was initially stored in the parallel inductors? f. How much energy is trapped in the ideal inductors? g. Do your solutions for i1 and i2 agree with the answer obtained in (f)?

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

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?

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