Which of the following is the most suitable material of construction for the condenser tubes, where the cooling medium is brine (salty water)?
Aluminium
Copper
Titanium
Stainless steel
Correct Answer :
C. Titanium
Related Questions
A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will
Increase
Decrease
Remain unaffected
May increase or decrease; depends on the thickness of each layer
__________ number determines whether the fluid flow in an open channel is supercritical, critical or sub-critical.
Mach
Reynolds
Froude
Weber
The mechanism which changes the value of manipulated variable in response to the output signal from the control unit is called the
Final control element
On-off control
Floating control action
None of these
A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place
The better insulation material should be put just next to pipe (i.e., inside)
The better insulating material should be put outside
Either of the insulating material could be put on either side
Steam temperature is considered before deciding as to which insulating material is to be put inside (i.e., just next to the pipe)
Dry saturated steam can be converted into superheated steam by
Increasing its cross-sectional area of flow
Passing it through a pressure reducing valve
Forcing it downwards through a vertical tube
None of these
Strain hardening effect in metals subjected to cold working is due to the __________ mechanism.
Slip
Fracture
Winning
Dislocation
Diffusion co-efficient of a metal in a solid solution depends upon its
Composition
Temperature
Both (A) & (B)
Neither (A) nor (B)
Euler number is defined as the ratio of inertia force to __________ force.
Pressure
Elastic
Gravity
Viscous
Silicon percentage in the silicon steel used for electrical appliances/equipments is
0.3-0.4
12-14
3-4
20-25
Minimum temperature upto which water can be theoretically cooled down in the cooling tower by evaporative cooling is equal to the __________ temperature of air.
Wet bulb
Dry bulb
Saturation
Dew point
Elimination of brittleness resulting from welding of saw blades is done by __________ of the welded portion.
Annealing
Toughening
Work hardening
Tempering
Carnot cycle is also termed as the constant __________ cycle in thermodynamics.
Entropy
Pressure
Volume
Heat
Cast iron contains __________ percent carbon.
2.5
3.75
4.75
5.25
Biological shield in a nuclear reactor is generally provided to protect against the
α-rays
β-rays
Gamma rays & neutrons
Electrons
Insulation of liquid surface can be achieved by __________ on top of its surface.
Floating hollow polypropylene spheres
Spraying alumina powder
Putting cement
None of these
In the X-ray radiography technique, the tube voltage for thicker plates as compared to thin plates, should be
Higher, as it gives higher wavelength
Lower, as it gives higher wavelength
Higher, as it gives shorter wavelength
Lower, as it gives shorter wavelength
__________ furnace is generally used in the non-ferrous foundries.
Direct arc
Indirect arc
Resistance
Induction
Annealing of cast iron
Softens it to facilitate machining
Decreases the free carbon
Increases the strength
None of these
A semi-conductor is damaged & behaves like a conductor, on passing a strong electric current through it, because it heats up the crystals & breaks the covalent bonds resulting in __________ electrons.
Lack of free
Excess of
Decrease in
None of these
The pressure drop per unit length for laminar flow of fluid through a long pipe is proportional to (where, A = cross-sectional area of the pipe & D = Diameter of the pipe)
A
D
1/A
1/A2
For grinding of softer materials, the grinding wheel should have __________ grain size.
Finer
Coarser
Medium
Any type of
Maximum change in the hardness of martensite occurs in the carbon content range of __________ percent in steel.
0.01 to 0.10
0.2 to 0.4
0.5 to 0.7
0.8 to 1.0
For preparation of porous bearings by powder metallurgy, preferred particle shape is
Spherical
Nodular
Irregular
No preferred shape
If the head is doubled in & centrifugal pump, the power required will increase in the ratio of
23
23/2
25/2
21/3
Which of the following pairs is not correctly matched?
Uranium - 233 : Fertile material
Binding energy : Mass defect
Scattering: Absorption cross-section
Number of nucleons : Mass number
The order of a chemical reaction
Can be determined only experimentally
Can be determined from the stoichiometry of the reaction
Cannot be zero
Can be fractional
Which of the following does not have a sharp melting point?
Thoria
Glass
Ice
Pig iron
Work study deals with the __________ study.
Time
Motion
Both (A) & (B)
Neither (A) nor (B)
The substance used as a smoke screen in warfare is
C2H2
SiCl4
P2O5
PCl5
Out of the following __________ iron has the best capability to bear sudden & excessive shocks.
White
Cast
Wrought
Pig