Fluid Mechanics and Thermal Sciences - Online Test
Q1. The demand and forecast for February are 12000 and 10275, respectively. Using
single exponential smoothening method (smoothening coefficient = 0.25),
forecast for the month of March is
Answer : Option C
Explaination / Solution:
No Explaination.
Q2. A smooth pipe of diameter 200mm carries water. The pressure in the pipe at
section S1 (elevation: 10m) is 50kPa. At Section S2 (elevation: 12m) the
pressure is 20kPa and velocity is 2ms-1. Density of water is 1000kgm-3 and
acceleration due to gravity is 9.8ms-2. Which of the following is TRUE?
Answer : Option C
Explaination / Solution:
No Explaination.
Q3. Match the following
P:Compressible flow U: Reynolds number
Q: Free surface flow V: Nusselt number
R: Boundary layer flow W: Weber number
S: Pipe flow X: Froude number
T: Heat convection Y: Mach number
Z: Skin friction coefficient
Answer : Option D
Explaination / Solution:
No Explaination.
Q4. A mono-atomic ideal gas ( γ = 1.67, molecular weight = 40) is compressed
adiabatically from 0.1MPa, 300K to 0.2MPa . The universal gas constant is
8.314kJkmol-1K-1. The work of compression of the gas (in kJ kg-1) is
Answer : Option A
Explaination / Solution:
No Explaination.
Q5. Consider the following two processes:
a. A heat source at 1200K loses 2500kJ of heat to sink at 800K
b. A heat source at 800K loses 2000kJ of heat to sink at 500K
Which of the following statements is TRUE?
Answer : Option B
Explaination / Solution:
No Explaination.
Q6. A fin has 5mm diameter and 100mm length. The thermal conductivity of fin
material is 400Wm-1K-1. One end of the fin is maintained at 130ºC and its
remaining surface is exposed to ambient air at 30ºC. if the convective heat
transfer coefficient is 40Wm-2K-1, the heat loss (in W) from the fin is
Answer : Option B
Explaination / Solution:
No Explaination.
Q7. A moist air sample has dry bulb temperature of 30ºC and specific humidity of
11.5g water vapour per kg dry air. Assume molecular weight of air as 28.93. If
the saturation vapour pressure of water at 30ºC is 4.24kPa and the total pressure
is 90kPa, then the relative humidity (in %) of air sample is
Answer : Option B
Explaination / Solution:
No Explaination.
Q8. In a steam power plant operating on the Rankine cycle, steam enters the turbine at
4MPa, 350ºC and exits at a pressure of 15kPa. Then it enters the condenser and exits as
saturated water. Next, a pump feeds back the water to the boiler. The adiabatic
efficiency of the turbine is 90%. The thermodynamic states of water and steam are
given in the table.
h is specific enthalpy, s is specific entropy and v the specific volume; subscripts f and g
denote saturated liquid state and saturated vapour state.
The net work output (kJ kg-1) of the cycle is
Answer : Option C
Explaination / Solution:
No Explaination.
Q9. In a steam power plant operating on the Rankine cycle, steam enters the turbine at
4MPa, 350ºC and exits at a pressure of 15kPa. Then it enters the condenser and exits as
saturated water. Next, a pump feeds back the water to the boiler. The adiabatic
efficiency of the turbine is 90%. The thermodynamic states of water and steam are
given in the table.
h is specific enthalpy, s is specific entropy and v the specific volume; subscripts f and g
denote saturated liquid state and saturated vapour state.
Heat supplied (kJ kg-1) to the cycle is
Answer : Option C
Explaination / Solution:
No Explaination.
Q10. Which of the following relationships is valid only for reversible processes undergone
by a closed system of simple compressible substance (neglect changes in kinetic
and potential energy?)
Answer : Option D
Explaination / Solution:
No Explaination.
