Hydraulic Machines MCQ - Constant Head Curves Part-1

1. Unit quantities are physical quantities _________
a) With numerical variables
b) Without numerical variables
c) With different sets
d) With unit difference

Answer: b
Explanation: Unit quantities are physical quantities without numerical variables. Unit is a way to assign measurement to any dimensional quantity.

2. Dyne cm is a Torque measurement unit.
a) true
b) false

Answer: a
Explanation: Dyne cm is a Torque measurement unit. One dyne is equal to 10-5 N. It is in accordance to the USCS (United States Customary units).

3.Unit quantities play an important role in determining the dimensional quantities.
a) true
b) false

Answer: a
Explanation: Yes, Unit quantities play an important role in determining the dimensional quantities as they denote the unit quantities usage and also its dimensions.

4. Unit power is developed by the turbine when the head of the turbine is unity.
a) true
b) false

Answer: a
Explanation: Yes, Unit power is developed by the turbine when the head of the turbine is unity. Unit power is one of the major quantities that influence the overall efficiency of the turbine and thus, plays an important role.

5. Constant head curves are also called as _______
a) Head race curves
b) Tail race curves
c) Main characteristic curves
d) Impeller curves

Answer: c
Explanation: Constant head curves are also called as main characteristic curves. It helps in determining the overall efficiency of the turbine by drawing curves with different set of parameters that play a major role in determining the performance of the turbine.

6. The speed of the turbine in a constant head curve is varied by __________
a) Temperature change
b) Reaction speed change
c) Changing the gate opening
d) Wheel speed change

Answer: c
Explanation: The speed of the turbine in a constant head curve is varied by maintaining a constant head. When we maintain a constant head, the speed of the turbine is varied by regulating the flow of fluid through a sluice gate.

7. Constant speed curves travel at constant speed when the value is equal to ______
a) 0
b) 1
c) 2
d) 3

Answer: b
Explanation: Constant speed curves detect the performance at different conditions. Characteristic curves of a turbine play an important role. It helps in determining the overall efficiency of the turbine by drawing curves with different set of parameters that play a major role in determining the performance of the turbine.

8. Power of a turbine is measured ______
a) Mechanically
b) Electrically
c) Chemically
d) Thermally

Answer: a
Explanation: Power of a turbine is measured mechanically by adjusting the flow of fluid using the percentage variations in a sluice gate. It helps in determining the overall efficiency of the turbine.

9. Which among the following is not a parameter to determine the efficiency of the turbine?
a) Unit speed
b) Unit power
c) Unit volume
d) Unit discharge

Answer: c
Explanation: Unit volume is not a parameter to determine the efficiency of the turbine. Power of a turbine is measured mechanically by adjusting the flow of fluid using the percentage variations in a sluice gate. It helps in determining the overall efficiency of the turbine.

10. Which among the following is not an important parameter to determine the performance of the turbine?
a) Speed
b) Discharge
c) Head
d) Volume of tank

Answer: d
Explanation: Volume of tank is not an important parameter to determine the efficiency of the turbine. These are not drawn in the curves pertaining its efficiency.