Pick out the wrong statement.
Geothermal energy is a non-conventional source of energy
Mass is converted into energy in both nuclear fission & fusion reaction
Inhalation of mercury vapour is not harmful for human beings
Inhalation of arsenic causes cancer
Correct Answer :
C. Inhalation of mercury vapour is not harmful for human beings
Related Questions
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
Alloying elements present in Haynes stellite, which has superior performance than high speed steel, are:
Nickel, cobalt & chromium
Tungsten, chromium & cobalt
Manganese, chromium & cobalt
Tungsten, molybdenum & nickel
Moist climate is the most favourable factor in the site selection far a
Steel plant
Textile factory
Petroleum refinery
Coke oven battery
Secondary hardening in steels arises out of the
Precipitation of fine alloy carbides at high temperatures
Refinement of ferrite grain size by working
Decomposition of retained austenite upon heat treatment
Precipitation of complex inter-metallic upon heat treatment
Main constituent of bone ash is
Ammonium phosphate
Calcium phosphate
Animal charcoal
Ammonium sulphate
Which of the following forces does not act on a fluid at rest?
Viscous force
Gravity force
Hydrostatic force
Surface tension force
Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as
Gr0.25, Gr
Gr0.25, Gr0.33
Gr, Gr0.25
Gr0.33, Gr0.25
Diffusion co-efficient of a metal in a solid solution depends upon its
Composition
Temperature
Both (A) & (B)
Neither (A) nor (B)
As per international norms, the maximum permissible value of noise level in the industrial environment is __________ decibels as measured at a distance of 1.5 metres from the source of noise.
110
85
60
45
Coating thickness in case of galvanising of steel sheet generally corresponds to the deposition of __________ gms of zinc per 
of steel strip.
5-10
1000-1500
120-500
1500-3000
Increasing the carbon content of steel
Reduces the upper shelf energy
Increasing the ductility transition temperature
Decreases brittleness
Decreases hardness
Heat transfer to the water wall in a high pressure water wall type boiler furnace is mainly by
Conduction
Convection
Radiation
Both 'a' & 'b'
Work hardenable alloy steel used to make the bucket wheel excavators, blades of bulldozers and other earth moving equipments contain iron, carbon and
Manganese
Silicon
Nickel
Chromium
__________ joint is usually used for joining cast iron pipes mostly used for temporary pipelines, where it may be necessary to dismantle & reassemble the pipeline very frequently.
Collar
Flanged
Bell and Spigot
Expansion
Which of the following is not a characteristic observed in material failure by fatigue fracture?
Plastic deformation of material does not occur
Initiation of crack from below the surface does not occur
Initiation of crack occurs on the surface of the machine part
Presence of both rough & smooth zone with conchoidal markings in smooth zone of the surface
Which of the following is not a ferromagnetic material?
Nickel
Cobalt
Aluminium
Iron
Direct conversion of thermal energy to electrical energy is facilitated by the
Fuel cells
Photo voltaic cell
Magneto hydrodynamic generator
None of these
Out of the following, the joint produced by __________ has the lowest strength.
Soldering
Welding
Brazing
Riveting
The most serious manufacturing defect from fracture toughness point of view is
Surface roughness
Pores
Spherical inclusion
Crack
The friction factor for the turbulent fluid flow in a rough pipe does not depend upon the
Pipe roughness & pipe diameter
Fluid velocity
Type of flowing fluid
Both 'b' & 'c'
The following thermocouple may be used for measuring temperature upto 1873°K.
Chromel-alumel
Copper-constantan
Platinum-platinum rhodium
Iron-constantan
'Flare tower' used in industry is meant for
Venting off (after burning) the excess inflammable/toxic gases at high pressure
Absorbing the pollutant gases from the furnace exhaust
Cooling of furnace exhaust gases
None of these
Surface tension of a liquid
Is due to intermolecular forces of cohesion
Decreases with rise in temperature
Is responsible for the spherical shape of an isolated liquid drop
All (A), (B) & (C)
Consider an ideal solution of components A and B. The entropy of mixing per mole of an alloy containing 50% B is
R ln 2
-R ln 2
3 R ln 2
-3R ln 2
Cementite is in the lamellar form in the __________ phase of steel.
Martenistic
Bainitic
Pearlitic
Ferritic
Tempering of a material does not improve its
Machinability
Toughness
Internal stress level
Softness
Solute atoms which cause yield point phenomenon in mild steel are/is
Aluminium
Boron
Carbon
Nitrogen
Temper brittleness of a material can be fairly detected by the __________ test.
Fatigue
Notched bar impact
Tensile
Hardness
Alloy powder manufactured by the following process have spherical shapes.
Electrochemical deposition
Gaseous reduction
Atomisation
Mechanical attrition
Which of the following contributes maximum as main source of sulphur in the blast furnace charge?
Sinter
Coke
Iron ore
Limestone