# Hydraulic Machines Questions and Answers – Unit Quantities Usage

This set of Hydraulic Machines Problems focuses on “Unit Quantities Usage”.

1. Which among the following is not a unit quantity of turbine?
a) Unit speed
b) Unit discharge
c) Unit power
d) Unit temperature

Explanation: Unit discharge, unit speed and unit power the three basic functions of the turbine. It plays an important role in determining the specific speeds and to increase the overall output efficiency of the turbine.

2. What does DMU stand for?
a) Density matter usage
b) Direct material usage
c) Density material usage
d) Depth matter usage

Explanation: DMU in hydraulic machines and turbo machinery stands for Direct material usage. It plays an important role in specifying the unit quantities.

3. Unit speed is the speed of the turbine operating under________
d) Draft tube

Explanation: Specific speed develops a unit power under a unit head of the turbine. The unit head of the turbine plays an important role in denoting the specific speed of the turbine. Unit speed is the speed of the turbine operating under one-meter head.

4. One dyne is equal to ________ N.
a) 10
b) 100
c) 1000
d) 10-5

Explanation: One dyne is equal to 10-5 N. It is in accordance to the USCS ( United States Customary units). Thus the correct option is ‘d’.

5. What is symbol for unit speed?
a) S
b) N
c) Ns
d) Nu

Explanation: The most commonly used symbol of unit speed is Nu. Unit speed is the speed of the turbine operating under one-meter head. Thus, the option is ‘c’.
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6. Unit speed of a single jet in a turbine is _______
a) 100 m/s
b) 300 m/s
c) 500 m/s
d) 800 m/s

Explanation: Unit speed of a single jet in a turbine is around 800 m/s. The most commonly used symbol of unit speed is Nu. Unit speed is the speed of the turbine operating under one-meter head. Thus, the option is ‘c’.

7. Unit speed is directly proportional to________
a) Head race distance
b) Specific speed
c) Pressure
d) Turbine performance

Explanation: Specific speed of a turbine is used to predict its turbine performance. Specific speeds are used in pumps to determine. Unit speed is directly proportional to its specific speed. Specific is takes place at the inlet and the outlet of the turbines.

8. Unit discharge is the discharge through the turbine when the head of the turbine is ________
a) High
b) Zero
c) Unity
d) Low

Explanation: Unit discharge is the discharge through the turbine when the head of the turbine is unity. Unit discharge is one of the major unit quantities that determine the overall efficiency of the turbine.

9. Unit discharge is denoted as _______
a) Du
b) Qu
c) Su
d) Nu

Explanation: The basic symbol of unit discharge is given as Qu. Unit discharge is the discharge through the turbine when the head of the turbine is unity. Unit discharge is one of the major unit quantities that determine the overall efficiency of the turbine.

10. Unit discharge is directly proportional to _______
a) Head race distance
b) Discharge of fluid in the turbine.
c) Pressure
d) Turbine performance

Explanation: Unit discharge is directly proportional to the discharge of fluid in the turbine. Unit discharge is the discharge through the turbine when the head of the turbine is unity. Unit discharge is one of the major unit quantities that determine the overall efficiency of the turbine.

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

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

12. Dyne cm is a Torque measurement unit.
a) True
b) False

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).

13. Unit quantities play an important role in determining the dimensional quantities.
a) True
b) False

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

14. Unit power is developed by the turbine when the head of the turbine is unity.
a) True
b) False

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.

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To practice all areas of Hydraulic Machines Problems, here is complete set of 1000+ Multiple Choice Questions and Answers.

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