Multiple choice

The following table of properties was printed out for saturated liquid and saturated vapour of ammonia. The titles for only the first two columns are available. All that we know is that the other columns (columns 3 to 8) contain data on specific properties, namely, internal energy (kJ/kg), enthalpy (kJ/kg) and entropy (kJ/kg.K).

             
T(0C)
P(kPa)

||||||| | -20 | 190.2 | 88.76 | 0.3657 | 89.05 | 5.6155 | 1299.5 | 1418.0 | | 0 | 429.6 | 179.69 | 0.7114 | 180.36 | 5.3309 | 1318.0 | 1442.2 | | 20 | 857.5 | 272.89 | 1.0408 | 274.30 | 5.0860 | 1332.2 | 1460.2 | | 40 | 1554.9 | 368.74 | 1.3574 | 371.43 | 4.8662 | 1341.0 | 1470.2 |

When saturated liquid at 40°C is throttled to -20°C, the quality at exit will be

  1. 0.189

  2. 0.212

  3. 0.231

  4. 0.788

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

constant wall temperature conditions and for turbulent flow,Nu=0.023$Re^{0.8}$$Pr^{0.33}$