High relative humidity decreases the evaporative process and as the temperature is increased, the relative humidity decreases. The comfort range for human body is the ambient temperature of 22 to 27°C with relative humidity ranging from __________ percent.
5 to 10
15 to 25
45 to 50
75 to 80
Correct Answer :
C. 45 to 50
Related Questions
Which of the following is the most wear resistant grade of carbide used for the cutting tools?
Aluminium carbide
Tungsten carbide
Nickel carbide
Iron carbide
Main constituent of bone ash is
Ammonium phosphate
Calcium phosphate
Animal charcoal
Ammonium sulphate
A dense structure of grinding wheel is not used for the
Ductile material
Hard materials
Brittle materials
Finishing cuts
More than 95% of __________ is present in corundum.
SiO2
Al2O3
CaSiO2
MgO
Presence of nickel & chromium in steel does not raise its
Elastic limit
Machining properties
Ductility
Resilience
What is the value of entropy at 273°K?
0
1
∞
None of these
The most economical channel section for the fluid flow is the one for which the discharge is maximum for a given cross-sectional area. Vertical velocity distribution in an open channel for laminar flow can be assumed to be
Parabolic
Hyperbolic
Straight line
None of these
Strain hardening effect in a metal subjected to cold working is due to the __________ mechanism.
Fracture
Dislocation
Slip
Twinning
The bank of tubes located at the back of the domestic refrigerators are the __________ tubes.
Refrigerant cooling
Evaporator
Condenser
Throttling
__________ is a special constituent of chlorophyll without which photosynthesis is not possible.
Calcium
Nitrogen
Phosphorous
Hydrogen
Gratings is associated with the measurement of
Linear displacement
Concavity/convexity
Surface texture
Flatness
Metal cutting by oxy-acetylene flame is accomplished by the __________ of the metal.
Burning
Intensive oxidation
Evaporation
None of these
Hot dipping process is used for coating a low melting point metal (e.g. Pb, Sn, Zn) on iron, steel & copper having relatively higher melting points. Which of the following is not a hot dipping process?
Galvanising
Tinning
Sherardizing
None of these
Which of the following metals cannot be hot worked at room temperature?
Zinc
Nickel
Lead
Tin
Lead is added to 60:40 brass primarily to improve
Machinability
Corrosion resistance
Fluidity
Strength
A form of stress corrosion failure termed as 'season cracking' is generally observed in
Thermosetting polymers
High carbon steels
Brasses
Borosilicate glasses
There are one octahedral void and __________ tetrahedral void in the closest packing of atoms.
One
Two
Three
None of these
Pressure exerted by a liquid depends upon its
Surface tension
Density
Viscosity
Buoyancy
Alloys having more than 80% copper are generally more
Abrasion resistant
Corrosion resistant
Prone to season cracking
Machinable
Young's modulus of a material is the measure of its
Stiffness
Malleability
Creep resistance
Tensile strength
Quartz is a __________ material.
Diamagnetic
Ferromagnetic
Ferroelectric
Piezoelectric
Machinability of hard alloys and tool steels is improved by
Spheroidising
Annealing
Tempering
Normalising
Two solutions A1 & A2 have pH value of 2 & 6 respectively. It implies that the solution
A1 is more alkaline than solution A2
A1 is highly acidic
A2 is very slightly acidic
Both (B) & (C)
During decarburising of a plain carbon steel, the thickness of ferrite layer growth is proportional to
Time
Square root of time
Square of time
Cube of time
Midrex process of sponge iron production uses reformed natural gas as the reducing agent, which uses iron ore in the form of
Lumps
Pellets
Briquettes
Sinter
The substance used as a smoke screen in warfare is
C2H2
SiCl4
P2O5
PCl5
High endurance limit of carburised machine parts is because of the fact that carburisation
Suppresses any stress concentration produced in the parts
Enhances the yield point of the material
Introduces a compressive layer on the surface
Produces a better surface finish
A material being tested for endurance strength is subjected to the __________ load.
Impact
Completely reversed
Dynamic
Static & dynamic
Use of flux during soldering is done to
Increase fluidity of solder by lowering its melting temperature
Prevent oxide formation
Wash away surplus solder
Full up the joint gap
In the blast furnace, incorporation of water vapour in the blast gives the following effect.
Increases the reducing potential of the gas
Increases the flame temperature
No significant change occurs
Increases the hydrogen content in the metal