Which of the following is true of dead zones? a. they are formed when a volcanic eruption covers the soil with ash. b. they are caused by an increase in the saltiness of the land, making the land infertile. c. they are formed when a specific area lacks nutrients and vitamins. d. they are formed when excess oxygen accumulates in a specific region. e. they are caused by algae blooms that occur when agricultural fertilizers and waste runoff enter natural waterways

When using the ohmmeter function of a digital multimeter, the leads are placed in what position relative to the component being tested? a. parallel b. control c. series d. line

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?