250+ TOP MCQs on Cascade Principle and Answers

Steam and Gas Turbines Multiple Choice Questions on “Cascade Principle”.

1. Arrangement of blades in an order to represent the blade ring in Turbo machinery is called as cascade.
a) True
b) False
Answer: a
Clarification: Cascade is an array of blades to represent the blade ring in turbo machinery.

2. Cascades __________ the efficiency.
a) decreases
b) increases
c) does not effect
d) none
Answer: b
Clarification: Cascades are introduced to improve the efficiency.

3. When steam is passed through the cascade the direction of air __________
a) reverse
b) remains the same
c) turned
d) cascade is nowhere related to direction
Answer: c
Clarification: When steam is passed through cascade its direction is reversed.

4. Across the turbine cascade static pressure _________
a) drops
b) increases
c) remains same
d) none of the mentioned
Answer: a
Clarification: Across the turbine cascade the static pressure drops.

5. Due to the formation of boundary layers on blades friction losses _________
a) remains the same
b) decreases
c) increases
d) none of the mentioned
Answer: c
Clarification: Due to the formation of boundary layers frictional losses increase due to viscous forces.

6. In compressor cascade when internal pressure is lost ____________
a) axial force is gained
b) axial force is reduced
c) efficiency reduces
d) none of the mentioned
Answer: a
Clarification: In compressor cascade when internal pressure is lost axial force is developed.

7. Drag force is parallel to lift force.
a) True
b) False
Answer: b
Clarification: Drag force is always perpendicular to lift force.

8. Due to viscosity lift force is __________
a) increased
b) decreased
c) remains constant
d) none
Answer: b
Clarification: Due to viscosity lift force is decreased.

9. Due to turbine cascade the drag ________ the lift.
a) increases
b) decreases
c) does not change
d) none of the mentioned
Answer: a
Clarification: Due to turbine cascade drag contributes some useful work which increases the lift.

10. Due to compressor cascade, the static pressure is __________
a) reduced
b) does not change
c) increased
d) none of the mentioned
Answer: c
Clarification: Due to compressor cascade viscous force decreased and hence static pressure is also decreased.