問題一覧
1
If the pressure on a confined gas in increased, the volume is decreases in accordance with Boyle's Law. When the pressure is retumed to its original value, the gas retum to its original volume. The gas has the property of.
volume elasticity
2
Cavitation is the result of
static pressure in a fluid becoming less than the fluid vapor pressure
3
The atomizer of a spray gun and the jets of a carburetor utilize
Bernoulli's Principle
4
Is a opening with a closed perimeter through which the fluids flows:
Orifice
5
Is an instrument which is used for measuring the discharge through pipes:
Venturi Meter
6
Is a conduit in which a liquid flow with free surface:
open Channel
7
On doubling the speed, N, of a centrifugal pump, all the following are true, except:
Head, horsepower, and volume flowrate are independently variable
8
Gases have no definite
all of these
9
Which of the following properties of water is not true?
it is compressible
10
A theorem that states," in steady flow the sum of the velocity head and the elevation head of any point is equal to the sum of corresponding heads at any other point plus or minus the losses in the head due to friction, plus if the last point is downstream from the first point, minus if upstream".
Bernoulli's Theorem
11
A law that states, "in equal volumes of gases with the same temperature and pressure the number of molecules is the same"
Avogadro's Law
12
A law that states, "when one or more liquids are put into a space of given volume the total pressure of the gas and vapor contained in the space is the sum of the separate pressures which each exert if were the only one present.
Dalton's Law
13
Is a tube usually bent in the form of U, containing a liquid of known specific gravity. the surface of which moves proportionally to the changes of pressure
Manometer
14
Is an overflow structure built across an open channel for the purpose of measuring the flow:
Weir
15
Is a graphical representation, with respect to any chosen datum of the potential head or energy which the liquid possesses at all sections of a pipe system
Hydraulic gradient
16
Is a conveying tube attached to the end of a pipe or hose which serves to increase the velocity of the issuing jet:
Nozzle
17
A kind if valve used on pipelines to prevent backilow of liquid
Check Valve
18
At sea level and normal temperature, atmosphere pressure is equivalent to
76cm column of Mercury
19
The vena contracta of a sharp-edged hydraulic orifice usually occurs
At a distance equal to about one half the orifice diameter downstream from the plane of the orifice.
20
A law in fluids which states, "At any point in a liquid at rest, the pressure is the same in all directions"
Pascal's Law
21
An essential part of a large dam and provides an efficient and safe means of releasing flow water that exceeds the design capacity of the reservoir.
Spillway
22
An instrument which measures the depth of rainfall:
Pluviometer
23
It is used mainly to completely close or completely open the line but not necessarily to control
Check Valve
24
It is used to control the flow of liquid.
Regulator Valve
25
The specific gravity of a substance is the ratio of its density to that of
water
26
A law that states, for a given mass of gas, the volume remaining constant, the pressure vanes directly as the temperature and directly as the density.
Charle's or Gay Lussac's Law
27
It is the point where the buoyant force and the centedine intersect each other.
Metacenter
28
What do you call the pressure which the fluid exerts on an immersed object or container walls?
Hydrostatic pressure
29
is used principally for alleviating the transient pressure in large pipeline system.
Standpipe
30
A law that states, "for a given mass of gas, the pressure remaining constant, the volume of gas varies directly as the absolute temperature."
Charle's or Gay Lussac's Law
31
The magnitude of the resultant of two forces is minimum when the angle between them is
180 degrees
32
Inward force that must be applied on the body to keep the body rotating in a circular motion.
centripetal
33
An object at rest may have
potential energy
34
The mass of a certain object is 10 grams, Is the expression F = ma valid on Mars ?
Newton's Law is valid in any internal system
35
The equivalent spring stiffness ke for two springs k, and k 2 in series is:
Ke = k+k2 /(Ki+K2)
36
Prefix Exa refers to
10 raise to 18
37
The equation of the curve formed by the path of a projectile is a
parabola
38
Impulse is the change in
momentum
39
Momentum is most closely related to
impulse
40
The mass of a certain object is 10 grams, What would its mass when taken to the plan Mars?
10g
41
The equivalent spring stiffness ke for two springs k 1 and k 2 in parallel is:
Ke = k1 + K2
42
The moment of inertia of an object does not depend on
its angular speed
43
Prefix Peta refers to
10 15
44
In terms of QH (eat from high temperature source) and QL (heat to low temperature sink), the network of the Camot cycle is:
W = QH - QL
45
The maximum thermal efficiency that can be obtained in an ideal reversible heat engine operating between 1540°F and 340°F is closest to.
60%
46
Pure water is boiling in an open pan at atmospheric pressure. Salt at a temperature equal to that of the boiling water is added. Immediately after the salt dissolves, which of the following will most likely to occur?
The boiling ceases
47
When cooled to a temperature approaching absolute zero, many materials have a sudden drop in their electrical resistivity to a value of almost zero. This phenomenon is known as
superconductivity
48
An inventor proposes to propel a ship by withdrawing heat from seawater and converting it all into work. Since the thermal energy of the sea is essentially unlimited, the ship could almost run forever without any fuel. This scheme fails because
it violates the second law of thermodynamics
49
Equilibrium conditions exists in all except which of the following:
in a steady flow system process
50
The heat transfer during adabalic procris is
zero
51
A pump is used to increase the pressure of the water entering the boiler of a steam power cycle. Which statement is true concerning the pump?
The enthalpy of the water leaving the pump is higher than the enthalpy of water entering.
52
Enthaipy of an ideal gas is a function only of:
temperature
53
Entropy is the measure of
randomness or disorder
54
An isentropic process is one which
is adiabatic and reversible
55
Name the process that has no heat transfer.
Isentropic
56
Which of the following thermodynamic cycles is the most efficient?
Carnot
57
Which of the following is a safety device on compressor?
Relief valve
58
In the deep well installation or operation, the difference between static water level and operating water level is called
suction lift
59
Energy changes are represented by all EXCEPT which one of the following.
dG = VdP +SdT
60
An economizer is used to....
heat the feedwater before it enters the boiler
61
What is the color code of steam pipe lines?
Sliver gray
62
The presence of oil or scale on boiler tubes causes...
Overheating
63
All of the following statements about the Carnot cycle are true EXCEPT
it is irreversible
64
Cooling air in intercoolers between compression stages in a multi-stage air compressor....
requires less horsepower for compressor than without intercoolers.