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| 1 | |
What is the specific humidity of air at 150 kPa whose dry bulb temperature is 20°C and relative humidity is 70%? |
| | A) | 0.000981 kg-wv/kg-da |
| | B) | 0.00382 kg-wv/kg-da |
| | C) | 0.00514 kg-wv/kg-da |
| | D) | 0.00686 kg-wv/kg-da |
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| 2 | |
Using saturated liquid water and 0°C as the reference state, what is the specific enthalpy of humid air at 120 kPa, 20°C, and 50% relative humidity? |
| | A) | 32.71 kJ/kg-da |
| | B) | 35.63 kJ/kg-da |
| | C) | 38.93 kJ/kg-da |
| | D) | 41.72 kJ/kg-da |
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| 3 | |
What is the dew-point temperature of humid air at 200 kPa, 30°C, and 55% relative humidity? |
| | A) | 10°C |
| | B) | 15°C |
| | C) | 20°C |
| | D) | 25°C |
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| 4 | |
Humid air at 150 kPa, 30°C, and 80% relative humidity undergoes an isobaric cooling process until its temperature is 25°C. Will any liquid condensate form during this process? |
| | A) | Yes |
| | B) | No |
| | C) | Not applicable |
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| 5 | |
Humid air is cooled, dehumidified and reheated during an isobaric process. Which one of the psychometric charts below correctly depicts these processes?
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| | A) | a |
| | B) | b |
| | C) | c |
| | D) | d |
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| 6 | |
One-hundred cubic meters per minute of humid air at 101 kPa, 35°C, 40% relative humidity is cooled to 25°C in a constant pressure process. The cooling rate for this process is: |
| | A) | 9.3 kW |
| | B) | 17.8 kW |
| | C) | 20.2 kW |
| | D) | 22.3 kW |
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| 7 | |
Saturated humid air at 101 kPa, 20°C is heated to 35°C during an isobaric process. What is the final relative humidity of this air? |
| | A) | 42% |
| | B) | 53% |
| | C) | 68% |
| | D) | 75% |
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| 8 | |
Humid air at 101 kPa, 35°C, 80% relative humidity is conditioned to 101 kPa, 25°C, 50% relative humidity. How much condensate is formed during this process? |
| | A) | 0.0087 kg/kg-da |
| | B) | 0.0168 kg/kg-da |
| | C) | 0.0193 kg/kg-da |
| | D) | 0.0231 kg/kg-da |
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| 9 | |
Humid air at 101 kPa, 35°C, 80% relative humidity is conditioned to 101 kPa, 25°C, 50% relative humidity. How much heat must be removed to accomplish this when the condensate leaves the system at 25°C? |
| | A) | 41.7 kJ/kg-da |
| | B) | 46.7 kJ/kg-da |
| | C) | 52.3 kJ/kg-da |
| | D) | 57.5 kJ/kg-da |
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| 10 | |
A standard atmospheric pressure cooling tower uses humid air at 30°C, 60% relative humidity to cool liquid water from 55°C to 40°C. Saturated humid air leaves this tower at 35°C. How much make-up water must be supplied to this tower? |
| | A) | 0.0206 kg/kg-da |
| | B) | 0.0313 kg/kg-da |
| | C) | 0.0347 kg/kg-da |
| | D) | 0.0404 kg/kg-da |
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