Consider a series rlc circuit driven by a sinusoidal voltage source of 1v amplitude and angular frequency, ω, radians/sec.

(a) derive an expression for the amplitude of the sinusoidal steady state voltage across the resistor, as a function of r, l, c, and ω.
(b) for r = 5 kω, l = 400 nh, and c = 4 nf, sketch this amplitude as a function of ω, for values ranging from 1 krad/s to 1 grade/is. what kind of a filter does this represent

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?