tough Steam and Gas Turbines questions and answers on “Turbine Rotor and Blade Stresses”.
1. Thermal stresses in rotor is ___________ than in cylinder.
a) lesser
b) greater
c) equal
d) none
Answer: b
Clarification: Pressure and Temperature are higher in high pressure cylinders and hence thermal stress in rotor is higher than that in cylinder.
2. Crank Nicholson method is an integration method.
a) True
b) False
Answer: a
Clarification: Crank Nicholson method is an integration method.
3. Westinghouse formula is used to calculate ____________ formula.
a) heat transfer
b) efficiency
c) heat transfer & efficiency
d) none of the mentioned
Answer: c
Clarification: Westinghouse formula is used to calculate heat transfer formula where heat transfer is to be found in third dimension.
4. Nagong-Haqi formula is used to calculate ___________ formula.
a) heat transfer
b) efficiency
c) heat transfer & efficiency
d) none of the mentioned
Answer: a
Clarification: Both westinghouse formula and nagong-haqi formula are used to calculate heat transfer formula.
5. Stress in the rotor is influenced by ______
a) Pressure
b) Temperature
c) Force
d) None of the mentioned
Answer: b
Clarification: Stress in rotor is influenced by temperature field.
6. When pulling stress and mechanical stress in same direction _______
a) Turbine efficiency decreases
b) Turbine shutdowns
c) Turbine slows down
d) None of the mentioned
Answer: d
Clarification: When pulling stress and mechanical stress in same direction, turbine shutdowns.
7. Turbine blades are subjected to stress from ___________
a) centripetal force
b) centrifugal force
c) centripetal & centrifugal force
d) none of the mentioned
Answer: b
Clarification: Turbine blades are subjected to stress from centrifugal forces.
8. Turbine blades are conventionally casted.
a) True
b) False
Answer: a
Clarification: Turbine blades can be conventionally casted.
9. In atomic scale shear stress varies ___________
a) tangentially & sinusoidally
b) tangentially
c) sinusoidally
d) none of the mentioned
Answer: c
Clarification: When shear stress in noted in atomic scale is varies sinusoidally.
10. Ductility increases with ____________ in temperature.
a) Increase
b) Decrease
c) Ductility doesn’t effect with temperature
d) None of the mentioned
Answer: a
Clarification: Ductility increases with an increase in temperature.
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