The values of enthalpy of steam at the inlet and outlet of a steam turbine in a
Rankine cycle are 2800kJ/kg and 1800kJ/kg respectively. Neglecting pump work,
the specific steam consumption in kg/kW-hour is

**A. ** 3.60

**B. ** 0.36

**C. ** 0.06

**D. ** 0.01

**Answer : ****Option A**

**Explaination / Solution: **

Work done by the turbine

Work done by the turbine

W = 2800 – 1800 = 1000 kJ/kg = 1000 kW-s/kg

Specific fuel consumption = (1/1000)×3600 = 3.6 kg / kw-hr

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In an experimental set-up, air flows between two stations P and Q adiabatically.
The direction of flow depends on the pressure and temperature conditions
maintained at P and Q. The conditions at station P are 150kPa and 350K. The
temperature at station Q is 300K. **A. ** 50

**B. ** 87

**C. ** 128

**D. ** 150

**Answer : ****Option B**

**Explaination / Solution: **

To cause the flow from P to Q, change in entropy (S_{P} - S_{Q}) should be
greater than zero

The following are the properties and relations pertaining to air:

Specific heat at constant pressure, C_{p} = 1.005kJ / kgK;

Specific heat at constant volume, Cv = 0.718kJ / kgK;

Characteristic gas constant, R = 0.287kJ / kgK

Enthalpy, h = CpT

Internal energy, u = CvT

If the air has to flow from station P to station Q, the maximum possible value of
pressure in kPa at station Q is close to

To cause the flow from P to Q, change in entropy (S

∴ The maximum value of pressure at Q = 87 kPa

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The emissive power of a blackbody is P. If its absolute temperature is doubled, the emissive
power becomes.

**A. ** 2P

**B. ** 4P

**C. ** 8P

**D. ** 16P

**Answer : ****Option D**

**Explaination / Solution: **

No Explaination.

No Explaination.

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The velocity profile of a fully developed laminar flow in a straight circular pipe, as shown in the
figure, is given by the expression u (r) = where dp/dx is a constant. The average
velocity of fluid in the pipe is

**A. ** -R^{2}/8μ (dp/dx)
**B. ** -R2/4μ (dp/dx)

**C. ** -R2/2μ (dp/dx)

**D. ** -R2/μ (dp/dx)

**Answer : ****Option A**

**Explaination / Solution: **

No Explaination.

No Explaination.

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Radiative heat transfer is intended between the inner surfaces of two very large isothermal parallel metal plates. While the upper plate (designated as plate 1) is a black surface and the warmer one being maintained at 727oC, the lower plate ( plate 2) is a diffuse and gray surface with an emissivity of 0.7 and is kept at 227oC. Assume that the surfaces are sufficiently large to form a two-surface enclosure and steady state conditions to exist. Stefan Boltzmann constant is given as 5.67 × 10-8 W/m2K4

**A. ** 17.0

**B. ** 19.5

**C. ** 23.0

**D. ** 31.7

**Answer : ****Option D**

**Explaination / Solution: **

No Explaination.

If plate 1 is also a diffuse and gray surface with an emissivity value of 0.8, the net radiation heat
exchange (in kW/m2) between plate 1 and plate 2 is

No Explaination.

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The figure below represents a triangle PQR with initial
coordinates of the vertices as P(1,3),Q(4,5) and R(5,3.5). The triangle
is rotated in the X-Y plane about the vertex P by angle θ in clockwise
direction. If sinθ= 0.6 and cosθ= 0.8, the new coordinates of the
vertex 𝑄 are

**A. ** (4.6, 2.8)

**B. ** (3.2, 4.6)

**C. ** (7.9, 5.5)

**D. ** (5.5, 7.9)

**Answer : ****Option A**

**Explaination / Solution: **

Since the triangle is rotated in CW direction, hence, for the new point
Q’ (x,y),

x > 4 and y < 5 __________(1)

and PQ = PQ’ or QR = Q’R’

Now we can get the answer easily by checking the option

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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.

**A. ** 498

**B. ** 775

**C. ** 860

**D. ** 957

**Answer : ****Option C**

**Explaination / Solution: **

No Explaination.

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

No Explaination.

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Consider an incompressible laminar boundary layer flow over a flat plate of length L, aligned with the direction of an incoming uniform free stream. If F is the ratio of the drag force on the front half of the plate to the drag force on the rear half,
then

**A. ** F < 1/2

**B. ** F = 1/2

**C. ** F = 1

**D. ** F > 1

**Answer : ****Option D**

**Explaination / Solution: **

No Explaination.

No Explaination.

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In a counter flow heat exchanger, hot fluid enters at 60^{o}C and cold fluid leaves
at 30^{o}C. Mass flow rate of the fluid is 1 kg/s and that of the cold fluid is 2 kg/s.
Specific heat of the hot fluid is 10 kJ/kgK and that of the cold fluid is 5 kJ/kgK.
The Log Mean Temperature Difference (LMTD) for the heat exchanger in ^{o}C is

**A. ** 15

**B. ** 30

**C. ** 35

**D. ** 45

**Answer : ****Option B**

**Explaination / Solution: **

No Explaination.

No Explaination.

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Match List-I with List-II and select the correct answer using the codes given
below the lists :

**A. ** 2 3 4 1

**B. ** 2 3 1 4

**C. ** 3 4 1 2

**D. ** 1 2 3 4

**Answer : ****Option A**

**Explaination / Solution: **

No Explaination.

Codes:

No Explaination.

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**Preparation Study Material**- Materials Science (Study/Preparation)
- Engineering Mechanics (Study/Preparation)
- Strength of Materials (Study/Preparation)
- Engineering Thermodynamics (Study/Preparation)
- Fluid Mechanics and Machinery (Study/Preparation)
- Manufacturing Technology I (Study/Preparation)
- Electrical Drives and Controls (Study/Preparation)
- Kinematics of Machinery (Study/Preparation)
- Manufacturing Technology II (Study/Preparation)
- Power-Plant Engineering (Study/Preparation)
- Engineering Materials and Metallurgy (Study/Preparation)
- Thermal Engineering (Study/Preparation)