Introduction to Hydraulics and Pneumatics
1.Heavy lifting work is often accomplished by shifting fluids in big machines. The power system of such machines can be described as
a) Reciprocating
b) Pneumatic
c) Hydraulic
d) Hybrid
2.The scientific
principle that makes hydraulic systems possible is
a) Pascal’s principle
b)
Boyle’s law
c) Bernoulli’s principle
d) The fluid flow principle
3.Which of the
following is not the application of hydraulics system?
a) Back hoe loader
b)
Spray Painting
c) Dumper
d) Fork
lift
4. Which of the
following reasons make water unsuitable to use as a fluid in hydraulic systems?
1.poor
lubrication
2.high viscosity
3.more leakage
4.quickly evaporates
a. 1
and 3
b. 2 and 4
c. 1, 3 and 4
d. all the above
5. Which of the
following statements are true?
1.low
viscosity fluids have higher leakage
2.high viscosity fluids have high pressure
drop
3.low viscosity fluids consume more power
4.low viscosity leads to wear of components
a. 1
and 2
b. 1, 2 and 3
c. 1, 2 and 4
d. 2, 3 and 4
6. In industrial
applications hydraulic fluids have viscosity grade ranging from
a. 20
to 50
b. 70 to 95
c.
46 to 68
d. 15 to 44
7. High viscosity
fluids have
a. low
pressure drop
b. less power consumption
c.
slow operation
d. all the above
8. What is viscosity
index?
a.
effect of pressure on changes in viscosity
b. effect of temperature
on changes in viscosity
c. effect of resistance between two
surfaces
d. none of the above
9. Highest temperature
at which a fluid in hydraulic system flows is called its pour point.
a.True
b.False
10. Which property
decides the behaviour of fluid when mixed with water?
a.
pour point
b.demulsibility
c.viscosity
d.oxidation
11. For any operation
in a hydraulic system the fluid should have pour point
a.
20 0F below the lowest temperature
b. 20 0F above the lowest
temperature
c. 20 0C below the lowest
temperature
d. 20 0C above the lowest
temperature
12. What is the disadvantage of petroleum based fluids?
a. low flash point
b. low density
c. light weight
d. all the above
13. How is the water
content in High Water Fluids (HFA) compared to oil content?
a. more
oil than water
b.
oil and water are in same proportion
c. more water than oil
d.
contains only water
14. A fluid used in
hydraulic systems should have
a. low
oxidation resistance
b. high oxidation resistance
c. high oxidation enhancing ability
d. none of these
15. At which pressure,
petroleum oil used in hydraulic systems gets compressed by 1/2 % ?
a. 70 bar
b. 40 bar
c. 30 bar
d. 95 bar
16. What is the
relation between temperature and specific weight for water glycol?
a. as temperature increases specific weight
decreases
b. as temperature increases specific
weight increases
c.
temperature and specific weight vary linearly
d. none
of the above
17. What is the
relation between temperature and viscosity for hydraulic oil?
a.
temperature and viscosity vary linearly
b. as temperature decreases viscosity
decreases at atmospheric pressure
c. as temperature increases viscosity decreases at atmospheric pressure
d. none of the above
18. Match the
following group 1 with group 2 and select the correct option:
|
Group 1 ---------------------------------------- |
Group 2 |
|
1. High water
fluids ---------------------------- |
A. water
and synthetic chemical |
|
2. water in
oil ------------------------------------ |
B. fire-resistant fluid |
|
3. water
glycol ----------------------------------- |
C. oil
in water |
|
4.
synthetics -------------------------------------- |
D. tiny
droplets of water in oil |
a. C – D – A – B
b. D – C – B – A
c. C – B – D – A
d. D – C – A – B
19. High Water Fluids
contain
a. oil in water
b. water in oil
c. only water
d.
none of the above
20. Viscosity of High
Water Fluids is
a.
greater than water
b. less than water
c. nearby water
d.
none of the above
21. Adding an additive
to water glycol fluids improves
a. flammability
b. viscosity
c. oxidation
d. all the above
22. Can all hydraulic
fluids be compressed when extremely large pressure is applied
a.Yes
b.No
23.The resistance
offered to the flow of fluid inside a piston develops into
a.pressure
b.force
c.stress
d.all of the above
24. At low pressures, liquids are
a. compressible
b. non-compressible
c. unpredictable
25.Which of the
following statements are false?
1.pressure
is resistance to flow
2.friction creates pressure
3.load cannot create pressure on the system
4.the pressure developed decreases if load
offers more resistance
a.
1, 2 and 4
b. 1 and 2
c. 3 and 4
d.
none of these
26. If no load is attached
to piston rod, the movement of piston assembly is possible when
a.
oil overcomes its self weight
b. oil overcomes friction in the piston
rod assembly
c. both a and b
d. none of these
27. During any operation in hydraulic system, oil prefers the path of
a. least resistance
b. maximum resistance
c. both a and b
d. none of the above
28.In a hydraulic
circuit a pump is provided with two outlet paths, one where load is attached
and other to the reservoir. Which path will the oil choose to flow first?
a.
oil will flow to the path where load is attached
b. oil will flow back to the reservoir first
c.
oil will flow through both the paths simultaneously
d. none of the above
29. Pressure applied
on a fluid in a container is equally distributed in all directions and acts
with
a.
equal force on equal areas parallelly
b. equal force on different areas and at
right angles
c. equal force on equal areas and at right angles
d. none of the above
30. Which law explains
the behavior of hydraulic fluids under pressure?
a.
Charles's law
b. Newtons law
c. Pascal's law
d.
None of the above
31. Flow of oil in a
pipe takes place due to
a.
balanced forces
b. unbalanced forces
c. both balanced and unbalanced forces
d. none of the above
