# Hydraulic Machines Questions and Answers – Main Parts of Centrifugal Pumps

This set of Hydraulic Machines Multiple Choice Questions & Answers (MCQs) focuses on “Main Parts of Centrifugal Pumps”.

1. A gear pump uses ___________
a) Petrochemical pumps
b) Meshing of gears
c) Froth pumps
d) Airlift pumps

Explanation: A gear pump uses meshing of gears. This meshing is done to pump fluid by displacement. Gear pumps are widely used in chemical installations.

2. The fundamental significance of all the turbomachinery is _______
a) Conservation of momentum
b) Conservation of mass
c) Conservation of heat
d) Conservation of speed

Explanation: The fundamental significance of all the turbomachinery is the conservation of momentum. It plays an important role in various turbomachinery.

3. The most common pump used for hydraulic fluid power application is __________
a) Centrifugal pumps
b) Gear pump
c) Froth pumps
d) Airlift pumps

Explanation: The most common pump used for hydraulic fluid power application is gear pump. A gear pump uses meshing of gears. This meshing is done to pump fluid by displacement. Gear pumps are widely used in chemical installations.

4. The change of angular momentum in a pump is equal to the _________
a) Sum of speeds
b) Sum of individual momentum
c) Sum of temperatures
d) Sum of energy transferred from a body

Explanation: The change of angular momentum in a pump is equal to the sum of individual momentum.

5. Conservation of angular momentum is described by _______
a) Newtons equation
b) Euler’s equation
c) Rutherford’s equation
d) Maxim equation

Explanation: Conservation of angular momentum is described by Euler’s equation. It states that the change of angular momentum in a pump is equal to the sum of individual momentum.

6. Gear pumps are mainly used in chemical installations because they pump ________
a) High viscosity fluids
b) High density fluids
c) High pressure fluids
d) High temperature fluids

Explanation: Gear pumps are mainly used in chemical installations because they pump high viscosity fluids. They use two external spur gears for this purpose.

7. Gear pumps convert rotational kinetic energy to hydrodynamic energy.
a) True
b) False

Explanation: Gear pumps are used to transport fluids. They transport fluids by conversion of energies. Gear pumps transport fluids by converting rotational Kinetic energy to hydrodynamic energy.

8. The inlet passage of centrifugal pump is controlled by ________
a) Gate
c) Turbine
d) Pump

Explanation: The inlet passage of water entry is controlled by the gate opening. The gate opening is an opening that sends only a percentage of fluid through the inlet passages for water to enter to the turbine.

9. Absolute exit velocity in a pump is denoted as ______
a) c2
b) v2
c) p2
d) w2

Explanation: Absolute exit velocity in a pump is denoted as ‘c2’.

10. Gear pumps are used to transport ________
a) Pressure
b) Speed
c) Power
d) Fluid

Explanation: Gear pumps are used to transport fluids. They transport fluids by conversion of energies. A gear pump uses meshing of gears. This meshing is done to pump fluid by displacement. Gear pumps are widely used in chemical installations.

11. Vertical Centrifugal pumps are also called as _________
a) Cantilever pumps
b) Hydrodynamic pump
c) Mechanical pump
d) Hydroelectric pump

Explanation: Vertical Centrifugal pumps are also called as cantilever pumps.

12. With the increase in load, Energy in the turbine________
a) Decreases
b) Increases
c) Remains same
d) Independent

Explanation: When there is an increase in the load, the energy in the turbine is drained off. Thus, to increase the energy, the by pass valve is opened to increase the amount of fresh steam entry. This increases the energy in the turbine.

13. The rotational kinetic energy comes from ______
a) Engine motor
b) Pump
c) Tank
d) Draft tube

Explanation: Centrifugal pumps transport fluids by converting rotational Kinetic energy to hydrodynamic energy. The rotational kinetic energy comes from engine or electrical motor.

14. When the balancing of the turbine is disturbed, we use ________
a) Throttle governing
b) Steam governing
c) Nozzle governing
d) Emergency governing

Explanation: When the balancing of the turbine is disturbed, we use emergency governing. These governors come into action only when there are emergencies in the turbine.

15. Gear pumps are ___________
a) Tangential flow pumps
b) Positive displacement pumps
c) Negative displacement pumps

Explanation: Gear pumps are positive displacement pumps or fixed displacement pumps. This means that they pump at a constant amount of fluid each revolution.

Sanfoundry Global Education & Learning Series – Hydraulic Machines.

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