A resonant six-turn loop of closely spaced turns is operating at 50 MHz. The radius of the loop is λ/30, and the loop is connected to a 50-ohm transmission line. The radius of the wire is λ/300, its conductivity is σ = 5.7 × 107 S/m, and the spacing between the turns is λ/100. Determine the:

a. the directivity of the antenna (in dB)
b. radiation efficiency taking into account the proximity effects of the turns
c. reflection efficiency gain of the antenna (in dB)

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

Carbon dioxide gas expands isotherm a turbine from 1 mpa, 500 k at 200 kpa. assuming the ideal gas model and neglecting the kinetic and potential energies, determine the change in entropy, heat transfer and work for each kilogram of co2.

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.