Question 41. Leiden-frost expansion is related to

Question 42. Consider an elemental control volume for mass balance continuity equation. Which one of the following is correct?

Question 43. Consider the following statements regarding nucleate boiling
(i) The temperature of the surface is greater than the saturation temperature of the liquid
(ii) Bubbles are created by the expansion of entrapped gas oil vapor at small cavities in the surface
(iii) The temperature is greater than that in film boiling
(iv) The heat transfer from the surface to the liquid is greater than that in the film boiling
Which of these statements are correct?

Question 44. The temperature of the liquid is below the saturation temperature and boiling takes place only in vicinity of the heated surface. This type of boiling is known as

Question 45. The boiling phenomenon is known to occur in how many forms?

Question 46. For water evaporating at atmospheric pressure, the burnout occurs at temperature excess slightly above

Question 47. The phenomenon of stable film boiling is referred to as

Question 48. In which type of boiling the temperature of the liquid exceeds the saturation temperature?

Question 49. In nucleate pool boiling, the heat flux depends on

Question 50. Estimate the peak heat flux for water boiling at normal atmospheric pressure. The relevant thermo-physical properties are
p f (liquid) = 958.45 kg/m³
p g (vapor) = 0.61 kg/m³
h f g = 2.25 * 10⁶ J/kg
σ = 0.0585 N/m