1. Radial flow reaction turbines are those turbines in which water flows ____________
a) Radial direction
b) Axial direction
c) Tangential direction
d) All of the mentioned
Explanation: The name itself indicates the type of flow that is radial direction but the thing that is unknown is whether it is radially inward or outwards.
2. Main parts of radial flow reaction turbines are ______________
a) Casing
b) Guide mechanism
c) Draft tube
d) All of the mentioned
Explanation: The main parts in a radial turbine are tight casing to prevent spill of water, runner, guide vanes, guide mechanism to regulate flow and draft to increase inlet pressure.
3. Radial flow reaction turbines contain spiral casing which area ____________
a) Remains constant
b) Gradually decreases
c) Gradually increases
d) Suddenly decreases
Explanation: Area of spiral structure gradually decreases because as discharge decreases correspondingly area also decreases. So, runner will rotate with constant velocity.
4. ____________ consists of stationary circular wheel all around the runner of turbine
a) Casing
b) Guide mechanism
c) Runner
d) Drafting
Explanation: Guide vanes are placed around the runner to regulate the flow and to provide shock less entry at inlet to runner.
5. The casing of radial flow reaction turbine is made of spiral shape, so that water may enter the runner__________
a) Variable acceleration
b) Constant acceleration
c) Variable velocity
d) Constant velocity
Explanation: Area of spiral structure gradually decreases because as discharge decreases correspondingly area also decreases. So, runner will rotate with constant velocity.
6. _____________ allow the water to strike the vanes fixed on runner without shock at inlet
a) Casing
b) Guide vanes
c) Runner
d) Draft tube
Explanation: Guide vanes are placed around the runner to regulate the flow and to provide shock less entry at inlet to runner.
7. Runner blades are made up of _____________
a) Cast steel
b) Cast iron
c) Wrought iron
d) Steel
Explanation: Runner blades are made up of cast steel because they are less corrosive and highly durable
8. The pressure at the exit of runner of reaction turbine is generally____________than atmospheric pressure
a) Greater
b) Lesser
c) Constant
d) Equal
Explanation: In general, the exit of runner has a low pressure compared to the atmospheric pressure.
9. ___________is a pipe of gradually increasing area used for discharging water from exit of the turbine to the tail race.
a) Casing
b) Guide mechanism
c) Draft tube
d) Runner
Explanation: Draft is a pipe of gradually increasing area, as water leaving runner has less pressure, draft tube will increase pressure energy of water by decreasing its velocity.
10. ____________governs the flow of water entering the runner blades.
a) Casing
b) Guide vanes
c) Draft tube
d) Runner
Explanation: Guide vanes are placed around the runner to regulate the flow and to provide shock less entry at inlet to runner.