In case of condensers & evaporators operating under given terminal conditions, LMTD (logarithmic mean temperature difference) for counter flow as compared to that for parallel flow is
More
Less
Equal
Much more
Correct Answer :
C. Equal
Related Questions
Depreciation of machines fails under the indirect expenses head. As per income tax regulations, it is calculated by the __________ method.
Diminishing balance
Sinking fund
Multiple straight line
Sum of the years digit
Potable water means the water used for
Fire-fighting
Cooling
Drinking
Evaporation to produce steam
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
More than 95% of __________ is present in corundum.
SiO2
Al2O3
CaSiO2
MgO
A solution which resists change in its pH value on addition of acid/alkali is called the __________ solution.
Neutral
Ideal
Buffer
Zero pH
Plastics as a material of construction suffer from the drawback of low
Machinability
Density
Strength
Plastic deformation
Primary designation of steel is based on its
Hardness & tensile strength
Carbon content
Iron content
Alloying elements content
Which of the following approaches the ideal gas behaviour most closely?
Wet steam
Saturated steam
Superheated steam
Saturated water
When the wavelength of incident X-rays increases, the angle of diffraction
Decreases
Increases
Remain constant
Shows no systematic variation
In a totally irreversible isothermal expansion process for an ideal gas, ΔE = 0, ΔH = 0. Then ΔQ and ΔS will be
ΔQ = 0, ΔS=0
ΔQ = 0, ΔS = +ve
ΔQ = 0, ΔS = -ve
ΔQ = +ve, ΔS= +ve
Hardening of steel is not possible, unless it is heated __________ critical point.
Above the highest
Above the lowest
Between the first & second
Between the second & third
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)
The maximum thickness of the metal which can be welded using ultrasonic welding is __________ mm.
0.5
3
10
25
The kinematic viscosity (in stoke) and the absolute/dynamic viscosity (in poise) are the same for __________ at room temperature.
Air
Water
Mercury
Alcohol
In a boundary layer developed along the flow, the pressure decreases in the downstream direction. The boundary layer thickness in this case will
Decrease gradually
Increase gradually
Increase rapidly
Remain constant
Flue gases pass through the following boiler accessories in a high pressure natural circulation boiler.
A. Induced draft fan
B. Economiser
C. Air preheater
D. Steam superheater Which of the following gives the correct sequence of flow of the flue gases through the above mentioned boiler accessories?
A, C, B, D
D, B, C, A
D, C, B, A
D, A, B, C
Routing in production, planning & control is concerned with the
Sequence of operation to be performed
Progress of work performed
Authorisation of work to be performed
Balancing of load on machines
A solid aluminium ball, when quenched in a water bath maintained at 40°C, cools down from 550°C to 450°C in 20 seconds. The expected temperature of the ball after next 20 seconds may be about __________ °C.
370
340
320
300
Dies for wire drawing are generally made of
Mild steel
Stainless steel
Carbides
High carbon steel
According to thermodynamic Fahrenheit scale, the fundamental interval between ice point to steam point is
180°
212°
32°
273°
Fibrous fracture is normally encountered in the __________ materials.
Hard
Elastic
Ductile
Brittle
The emf of a Deniell cell Zn | Zn2+ || Cu2+ | Cu can be increased by
Decreasing the surface area of the electrodes
Increasing the concentration of zinc sulphate solution
Increasing the surface area of the electrodes
Increasing the concentration of copper sulphate solution
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 activity of pure hydrogen gas at 1000°C and 5 atm pressure
Is always less than 1
Is always greater than 1
Can be 5
Depends on the choice of the standard state
__________ is the most important element, which controls the physical properties of steel.
Manganese
Silicon
Carbon
Vanadium
Pick out the correct statement
Jet engine can work, where there is no atmosphere
Rocket engines cannot work, where there is no atmosphere
Rocket engines carry oxygen required for the combustion in the form of oxidiser
Jet engines also carry oxidiser
Addition of silicon to cast iron
Promotes graphite module formation
Improves its ductility
Does not promote graphite flakes formation
Increases the fluidity of molten metal
Corrosion is
A physical phenomenon
A chemical phenomenon
Same as erosion
An uncontrollable phenomenon
For grinding of softer materials, the grinding wheel should have __________ grain size.
Finer
Coarser
Medium
Any type of
Pick out the wrong statement about coating/electroplating of metals.
Phosphate coating is used as an excellent base for paints & enamels
Phosphate coating is less corrosion resistant than chromate coating
The base metal to be electroplated is normally made the cathode of the electrolytic cell and coating metal is made the anode
Calorising is the process of coating steel with chromium