Question 2) your cell phone operates at 1.9 ghz and transmits with an electric field strength of 100 v/m. assume air has a conductivity of 2 x 10−6 s/m, and a relative permittivity of ϵr=1 if the receiver in the cell tower can detect 100 mv/m, how far away can you still connect (in terms of m and enter your answer with at least 5 significant digits)? (assume the only effect is attenuation in the signal due to distance; ie not reduced from isotropic radiation).

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

Acompressor receives the shaft work to decrease the pressure of the fluid. 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?