__________ remains constant during the adiabatic cooling of moist air.
Wet bulb temperature
Dry bulb temperature
Relative humidity
Specific humidity
Correct Answer :
A. Wet bulb temperature
Related Questions
Constituents of stellite are
Zinc, copper & nickel
Cobalt, chromium & tungsten
Zinc, aluminium & nickel
Nickel, cobalt & vanadium
Tempering of a material does not improve its
Machinability
Toughness
Internal stress level
Softness
__________ number determines whether the fluid flow in an open channel is supercritical, critical or sub-critical.
Mach
Reynolds
Froude
Weber
Which of the following is the largest quantum of pressure?
1 kg/cm2
1 bar
1 atmosphere
1 kilo Pascal
The refractory brick which has good thermal shock resistance at high temperature but cracks on cooling below 400°C is
Magnesite
Chrome
Silica
Fireclay
Which of the following hardness tests does not measure the indentation hardness of metals and alloys?
Vickers hardness test
Shore scleroscope test
Brinell hardness test
Rockwell hardness test
__________ can replace tungsten in high speed steel.
Chromium
Vanadium
Cobalt
Molybdenum
Cold working of a material results in increase in hardness, which is termed as the __________ hardening.
Cold
Work
Age
Induction
Which of the following material handling equipments is not suitable for moving materials in varying paths?
Hand trolley
Belt conveyor
Crane
Truck
Identify the false statement
Martensitic steels are less susceptible to pitting corrosion than austenitic steels
Pitting corrosion is usually very localised
Hydrogen embrittlement is facilitated by tensile stress
Stress corrosion cracking is facilitated by tensile stress
Hot extrusion of aluminium is done in the temperature range of __________ °C.
550-600
450-500
350-400
250-300
Laser is a device to produce
Gamma rays
Microwaves
A beam of white light
A beam of coherent light
Solidification time of a molten metal in a casting is proportional to (where, V = volume of metal & A = its surface area; in the casting)
V/A
V/A2
V2/A
V2/A2
Potable water means the water used for
Fire-fighting
Cooling
Drinking
Evaporation to produce steam
__________ of test specimens is not involved in any hardness testing method.
Fracture
Indentation
Wear
Scratch
Pick out the wrong statement.
Ductile fracture of a stressed material, which exhibits a large plastic deformation is commonly caused by the formation and coalescence of voids in the necked region
Brittle fracture is caused by the propagation of pre-existing cracks in the material and involves minimum plastic deformation
Fatigue fracture of a material is always brittle in nature and takes place due to the existence of line imperfections
Brittle materials are generally tested in tension
A 2 kg object weighs 1.8 kgf on a spring balance. The value of 'g' at that location in m/sec2 is
8.82
9.81
10.88
0.95
Gas turbine normally employs a constant __________ cycle.
Pressure
Temperature
Volume
None of these
The most important consideration in value engineering is the
Profit maximisation
Customer satisfaction
Cost reduction
Process improvement
The expected efficiency of a single riveted lap joint is of the order of 50%. If the thickness of the plate is increased four times, then the rivet diameter will have to be increased __________ times.
Two
Four
Six
Eight
In __________ process, there is an increase in entropy with no degradation of energy.
Isothermal expansion
Isochoric heat addition
Polytropic expansion
Isobaric heat addition
With increase in compression ratio, the volumetric efficiency of air compressor
Increases
Decreases
Remain same
May increase or decrease (depends on the suction pressure)
Pick out the wrong statement about nucleate boiling.
Bubble generation is by expansion of entrapped gas/vapour at small cavities in the surface
Surface temperature is greater than the saturation temperature of the liquid
Heat transfer from the surface of the liquid is less than that in film boiling
The temperature is less than that of film boiling
Case hardening is not done by
Nitriding
Hot dipping
Electroplating
Both b & c
The hardenability of steel decreases with
Decrease in dislocation density
Increase in solutionising temperature
Increase in strength
Decrease in grain size
As the fluid flow rate increases, the float of the Rotameter
Rises in the tube
Rotates at higher speed
Rotates at lower speed
Drops down in the tube
The capacity of a spring to store energy is called the spring form co-efficient. Stiffness of a spring is measured by the
Ability to absorb shock
Capacity to store energy
Ratio of the wire & coil diameters
Load to produce unit deflection
__________ is a special constituent of chlorophyll without which photosynthesis is not possible.
Calcium
Nitrogen
Phosphorous
Hydrogen
Air-petrol ratio in an automotive petrol engine is around
14 : 1
22 : 1
25 : 1
4 : 1
The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1 - T2)/T1. The co-efficient of performance (CO.P.) of a Carnot heat pump operating between T1 and T2 is given by
T1/(T1-T2)
T2/(T1-T2)
T1/T2
T2/T1