Q.1
The degree of saturation is the ratio of
  • (saturated specific humidity / actual specific humidity)^2
  • 1/(saturated specific humidity * actual specific humidity)
  • saturated specific humidity / actual specific humidity
  • actual specific humidity / saturated specific humidity
Q.2
When humidity ratio of air          air is said to be dehumidified.
  • increases
  • decreases
  • remains constant
  • none of the mentioned
Q.3
The total entropy of a mixture of gases is the          of the partial entropies.
  • average
  • weighted mean
  • sum
  • difference of the highest and the lowest
Q.4
The expression which represents the pressure exerted by a gas is
  • nvrt
  • nrt/v
  • v/nrt
  • 1/nvrt
Q.5
The slope of sublimation curve is          the slope of the vaporization curve at triple point.
  • equal to
  • less than
  • greater than
  • none of the mentioned
Q.6
An application requires R-at −140°C. The triple-point temperature is −157°C. Find the pressure of the saturated vapour at the required condition.
  • 0.0058 kpa
  • 0.0098 kpa
  • 0.0068 kpa
  • 0.0088 kpa
Q.7
At the triple point, l(sublimation) = l(vaporization) – l(fusion).
  • true
  • false
Q.8
Water          on melting and has the fusion curve with a          slope.
  • contracts, negative
  • contracts, positive
  • expands, negative
  • expands, positive
Q.9
The properties of liquid            with pressure.
  • do not vary
  • vary largely
  • vary little
  • none of the mentioned
Q.10
When does a vapour become superheated?
  • when the temperature of vapour is less than the saturation temperature at given pressure
  • when the temperature of vapour is more than the saturation temperature at given pressure
  • when the temperature of vapour is equal to the saturation temperature at given pressure
  • none of the mentioned
Q.11
The slopes of sublimation and vaporization curves for all substances are
  • negative
  • positive
  • zero
  • none of the mentioned
Q.12
The Clausius-Clapeyron equation is given by
  • dp/dt = l / t(vf+vi)
  • dp/dt = l / t(vf-vi)
  • dt/dp = l / t(vf+vi)
  • dt/dp = l / t(vf-vi)
Q.13
For proper utilization of exergy, it is desirable to make first law efficiency           and the source and use temperatures should
  • as close to unity, be different
  • as close to unity, match
  • as close to zero, match
  • as close to zero, be different
Q.14
A pure substance which exists in a single phase has          independent variables.
  • zero
  • one
  • two
  • three
Q.15
If a relation exists among variables x,y,z then z may be expressed as a function of x and y as, dz=Mdx+Ndy .
  • true
  • false
Q.16
If work is involved, Amin=          and if heat is involved, Amin=
  • w, q(1+to/t)
  • w, q(1-to/t)
  • q(1+to/t), w
  • q(1-to/t), w
Q.17
If solar energy Qr is available at a reservoir storage temperature of Tr and if quantity of heat Qa is transferred by the solar collector at temperature Ta, then which of the following is true?
  • first law efficiency = qa/qr
  • second law efficiency = exergy output / exergy input
  • second law efficiency = (first law efficiency)*(1-to/ta)/(1-to/tr)
  • all of the mentioned
Q.18
1 mole of cyclohexane (z = 1.is filled in a container at 27oC and 4 atm, what is the volume of container?
  • 3.8 liter
  • 4.4 liter
  • 5.6 liter
  • 7.4 liter view answer
Q.19
With the concept of exergy available, which of the following is possible?
  • to analyse means of minimizing the consumption of available energy to perform a given process
  • to ensure most efficient possible conversion of energy
  • both of the mentioned
  • none of the mentioned
Q.20
Which of the following is true about compressibility of real gases?
  • z = 1
  • z < 1
  • z > 1
  • both z < 1 and z > 1 view answer
Q.21
The first law efficiency is defined as the ratio of the output energy to the input energy.
  • true
  • false
Q.22
The following also gave two-constant equations of state.
  • berthelot
  • dieterici
  • redlich-kwong
  • all of the mentioned
Q.23
The rate at which entropy is transferred out must          the rate at which entropy enters the control volume.
  • be less than
  • equal to
  • exceed
  • none of the mentioned
Q.24
The temperature of feedwater leaving a heater is          the saturation temperature at steam extraction pressure.
  • less than
  • equal to
  • more than
  • none of the mentioned
Q.25
The rate of entropy increase of the control volume          or          the net rate of entropy transfer to it.
  • exceeds or is less than
  • exceeds, is equal to
  • is less than, or equal to
  • none of the mentioned
Q.26
How many types of feedwater heaters are present?
  • one
  • two
  • three
  • four
Q.27
A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature of 350°C and the Condenser atkPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle?
  • 7.7
  • 17.7
  • 27.7
  • 37.7
Q.28
Any thermodynamic process is accompanied by entropy generation.
  • true
  • false
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