A. Less
B. More
C. Same
D. Unpredictable
Related Mcqs:
- At equilibrium the concentration of water in vapour phase (C*) in kg/m3 of air space and the amount of water (m) adsorbed per kg of dry silica gel are related by, C* = 0.0667m. To maintain dry conditions in a room of air space 100m3 containing 2.2 kg of water vapour initially, 10 kg of dry silica gel is kept in the room. The fraction of initial water remaining in the air space after a long time (during which the temperature is maintained constant) is_________________?
A. 0.0
B. 0.2
C. 0.4
D. 1.0 - A 25 cm × 25 cm × 1 cm flat sheet weighing 1.2 kg initially was dried from both sides under constant drying rate conditions. It took 1500 seconds for the weight of the sheet to reduce to 1.05 kg. Another 1m × 1m × 1cm flat sheet of the same material is to be dried from one side only. Under the same constant drying rate conditions, the time required for drying (in seconds) from its initial weight of 19.2 kg to 17.6 kg is ____________________?
A. 1000
B. 1500
C. 2000
D. 2500 - An air-water vapour mixture has a dry bulb temperature of 60°C and a dew point temperature of 40°C. The total pressure is 101.3 kPa and the vapour pressure of water at 40°C and 60°C are 7.30 kPa and 19.91 kPa respectively. The humidity of air sample expressed as kg of water vapour/kg of dry air is__________________?
A. 0.048
B. 0.079
C. 0.122
D. 0.152 - It takes 6 hours to dry a wet solid from 50% moisture content to the critical moisture content of 15%. How much longer it will take to dry the solid to 10% moisture content, under the same drying conditions? (The equilibrium moisture content of the solid is 5%) ?
A. 15 min
B. 51 min
C. 71 min
D. 94 min - Unsaturated air (with dry and wet bulb temperatures being 35 and 25°C respectively) is passed through water spray chamber maintained at 35°C. The air will be__________________?
A. Cooled
B. Humidified
C. Both A. & B.
D. Dehumidified - Unsaturated air (with dry bulb temperature and dew point being 35°C and 18°C respectively) is passed through a water spray chamber maintained at 15°C. The air will be cooled_________________?
A. And humidified
B. And dehumidified with increase in wet bulb temperature
C. At the same relative humidity
D. And dehumidified with decrease in wet bulb temperature - Unsaturated air (with dry bulb and wet bulb temperatures being 45°C and 25°C respectively) is passed through a water spray chamber maintained at 23°C. The air will be cooled and _________________?
A. Humidified with wet bulb temperature decreasing
B. Humidified at constant wet bulb temperature
C. Dehumidified
D. None of these - A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids)) ?
A. M(Xo – XF)
B. M(Xo/XF)
C. M ln(Xo/XF)
D. MXo ln(Xo/XF) - A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids))_____________?
A. M(Xo – XF)
B. M(Xo/XF)
C. M ln(Xo/XF)
D. MXo ln(Xo/XF) - For the air water system under ambient conditions, the adiabatic saturation temperature and the wet bulb temperature are nearly equal, because__________________?
A. Water has a high latent heat of evaporation
B. Lewis number is close to unity
C. They are always equal under all circumstances
D. Solubility of the components of air in water is very small
