EEN 125A-S2-2020- 2-Reflections. par
Question 3
Determine the following for Figure 3.
R1
5
R2
3
1. Total Impedance
2. Total Current
3. Total Voltage
4. Reactive Power
5. Apparent Power
6. Inductor value for power factor
improvement to 0.9 lagging.
Li
j30
C
-315
Impedance, voltage and currents in
polar notation
Figure 3 - Parallel AC network
Active Power (P) = 2000 W and Frequency = 100 Hz

Ahot wire operates at a temperature of 200°c while the air temperature is 20°c. the hot wire element is a tungsten wire of 5 um diameter and 2 mm in length. plot using excel current, heat transfer and heat generated by the wire for air velocity varying from 1-10 m/s in steps of lm/s? matlab the sensor voltage output, resistance, or assume nu 0.989 re033pr13 take air properties at tr (200°c20°c)/2 = 110°c properties of tungsten: c 0.13 kj/kg. k 3 p 19250 kg/m k (thermal conductivity) = 174 w/m. k

An engine runs on the ideal diesel cycle. the cycle has a compression ratio of 20 and a cutoff ratio of 2. the highest temperature in the cycle is 1200 k. if the heat into the system is 300 kj/kg of working fluid and using variable specific heats determine the work produced per mass of working fluid

10 kg of co2 is initially contained at 400 kpa and 300 k. the gas constant for carbon dioxide is 189 j/lkg k) and has a specific heat ratio, k, of 1.289. isentropic expansion then occurs until the pressure is 200 kpa. a) determine the initial volume of co2 in m. b) determine the final temperature in k. c) determine the work done by the system during the expansion kl.