2. For the following circuit, the initial current through the inductor is zero. a. Find the energizing equations for vL and iL when the switch is moved to position 2. b. Find the de-energizing equations for vL and iL when the switch is moved from position 2 to position 3. c. Find the de-energizing equations for vL and iL when the switch is moved from position 2 to position 1. d. Find the de-energizing equations for vL and iL when the switch is moved from position 2 to an open position. e. Calculate and plot vL and iL at 0, 1, 2, 3, 4

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?

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented

Burgers vector is generally parallel to the dislocation line. a)-true b)-false