Category: Steam and Gas Turbines Objective Questions

Steam and Gas Turbines online test on “Film Coefficient, Pressure Losses and Regenerator Effectiveness”.

1. Film coefficient is also known as heat transfer coefficient.
a) True
b) False
Answer: a
Clarification: Film coefficient is also known as heat transfer coefficient.

2. Film coefficient is the proportionality coefficient between heat flux and ___________
a) opposing force
b) driving force
c) opposing & driving force
d) none of the mentioned
Answer: b
Clarification: Film coefficient is the proportionality coefficient between heat flux and driving force.

3. Film coefficient is represented by _______
a) t
b) g
c) h
d) f
Answer: c
Clarification: Heat transfer coefficient is represented by h.

4. ___________ is used in phase transition process.
a) Film coefficient
b) Pressure coefficient
c) Mean temperature
d) None of the mentioned
Answer: a
Clarification: Film coefficient is used in phase transition process.

5. Film coefficient is _________ of thermal insulance.
a) directly proportional
b) inverse
c) equal
d) none of the mentioned
Answer: b
Clarification: Film coefficient is inverse of thermal insulance. Film coefficient is the inverse of the resistance offered by the material towards heat.

6. Ratio of thermal conductivity to the length scale is known as __________
a) Film coefficient
b) Heat transfer coefficient
c) Film & Heat transfer coefficient
d) None of the mentioned
Answer: c
Clarification: Ratio of thermal conductivity to length is known as film coefficient.

7. Nusselt number has ________
a) no dimension
b) dimension
c) no units
d) none of the mentioned
Answer: a
Clarification: Nusselts number is a dimensionless number. Nusselt’s number is used in calculating heat transfer.

8. Overall heat transfer coefficient is represented by _______
a) K
b) A
c) U
d) I
Answer: c
Clarification: Overall heat transfer coefficient is represented by U.

9. Nusselts number applies to _______
a) Laminar flow
b) Turbulent flow
c) Laminar & Turbulent flow
d) None of the mentioned
Answer: c
Clarification: Nusselts number is applicable to both laminar and turbulent flow.

10. Mass flux is denoted by ______
a) J
b) G
c) U
d) None of the mentioned
Answer: a
Clarification: Mass flux is represented by j.

Steam and Gas Turbines for online test,

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Steam and Gas Turbines Multiple Choice Questions on “Turbine Casting and Exhaust Frames”.

1. Exhaust frame and exhaust diffuser are connected ____________
a) one after other
b) together
c) not connected
d) none of the mentioned
Answer: b
Clarification: Exhaust frame and exhaust diffuser are connected together. Gases coming out of exhaust frames has high pressure and when connected to diffuser pressure energy is converted into velocity.

2. Exhaust frame is connected to the _________
a) aft flange
b) diffuser
c) aft flange & diffuser
d) none of the mentioned
Answer:c
Clarification: Exhaust frame is connected to the aft flange and also diffuser. Exhaust frame is connected to diffuser using aft flange.

3. Aft flange is present on the turbine shell.
a) True
b) False
Answer: a
Clarification: Aft flange is present on the turbine shell.

4. _____________ are further divided in outer cylinder and inner cylinder.
a) Aft flange & Exhaust frame
b) Aft flange
c) Exhaust frame
d) None of the mentioned
Answer: c
Clarification: Exhaust frames are further divided in outer cylinder and inner cylinder. Inner cylinder of exhaust frame has parts used to connect to diffuser.

5. In exhaust frames inner and outer cylinder are connected using __________
a) structs
b) aft flange
c) structs & aft flange
d) none of the mentioned
Answer: a
Clarification: Structs are used to connect both inner and outer cylinder in exhaust frame. Where as aft flange is connected to outer casing of the exhaust frame.

6. Exhaust diffuser is located at extreme _________
a) aft flange
b) aft end
c) exhaust frame
d) none of the mentioned
Answer: b
Clarification: Exhaust diffuser is located at extreme aft end. Where one end of aft flange is connected to exhaust frame.

7. Exhaust diffuser is supported by exhaust frame.
a) True
b) False
Answer: a
Clarification: Exhaust diffuser is supported by exhaust frame.

8. __________ are present at the end of exhaust diffuser.
a) Guide vanes
b) Stationary vanes
c) Guide & Stationary vanes
d) None of the mentioned
Answer: c
Clarification: Guide vanes are present at the end of exhaust diffuser. Stationary vanes are used to guide the working fluid in the required direction and hence they are also called as guide vanes.

9. Struts supporting inner and outer cylinder are to be maintaned at _______ temperature.
a) increasing
b) variable
c) constant
d) none of the mentioned
Answer: c
Clarification: When temperature is not constant thermal stresses developed and center position may vary.

10. Cooling air is made to flow through the gaps in between struts.
a) True
b) False
Answer: a
Clarification: Cooling air is made to flow so that the temperature remains constant.

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