GATE Solved Questions on Properties of Pure Substance
Question 1. Given below is an extract from steam tables.
| Temperature(°C) |  (bar) |
Specific volume ( ) |
Enthalpy (kJ/kg) | ||
| Saturated liquid | Saturated Vapour | Saturated liquid | Saturated vapour | ||
| 45 | 0.09593 | 0.001010 | 15.26 | 188.45 | 2394.8 |
| 342.24 | 150 | 0.001658 | 0.010337 | 1610.5 | 2610.5 |
Specific enthalpy of water in kJ/kg at 150 bar and 45°C is
(A) 203.60
(B) 200.53
(C) 196.38
(D) 188.45
GATE-ME-2006
Hint 1. (Ans A)
Specific volume in compressed liquid region does not change with pressure as water is incompressible.
Question 2. Water has a critical specific volume of 0.003155 
. A closed and rigid steel tank of volume 0.025 
contains a mixture of water and steam at 0.1 MPa. The mass of the mixture is 10 kg. The tank is now slowly heated. The liquid level inside the tank
(A) will rise
(B) will fall
(C) will remain constant
(D) may rise or fall depending on the amount of heat transferred
GATE-ME-2007
Hint 2. (Ans A)
After heating at constant volume it goes into liquid region. Hence the level of liquid in the vessel rises.
Question 3. The pressure, dry bulb temperature and relative humidity of air in a room are 1 bar, 30°C and 70 %, respectively. If the saturated steam pressure at 30°C is 4.25 kPa, the specific humidity of the room air in kg water vapour / kg dry air is
(A) 0.0083
(B) 0.0101
(C) 0.0191
(D) 0.0232
GATE-ME-2013
Hint 3. (Ans C)
Answer keys
1. (A) 2. (A) 3. (C)
One Response to “Previous year GATE MCQ’s on Properties of Pure Substance”
karan
why do u think it is a duplicate comment?