Which of the following is not the function of a volute casing provided in a centrifugal pump?
To reduce the head loss in discharge
To increase the pump efficiency
To collect liquid from the periphery of the impeller and to transmit it to the delivery pipe at constant velocity
To increase the pump discharge rate
Correct Answer :
D. To increase the pump discharge rate
Related Questions
Pick out the wrong statement.
Lead can creep under its own weight at room temperature
The electrical conductivity of gold is considerably reduced by alloying additions due to the decrease in electron movement
Recrystallisation temperature decreases with decrease in strain in a cold worked metal
With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase
Large scale fire on fuel gas line is normally extinguished by
Water
Steam
Foam
Nitrogen
Powder metallurgy technique is used in the production of __________ tools.
Tungsten carbide
High carbon steel
High speed steel
Drilling
Which of the following can be manufactured using powder metallurgy techniques?
Brake linings
Bearings
Carbide tool tips
All 'a', 'b' and 'c'
Pick out the wrong statement about the machinability of metals. Machinability of a metal
Decreases with increase in strain hardening tendencies
Decreases with increase in hardness, in general
Depend on the composition, microstructure and physical & mechanical properties
Decreases with increases in tensile strength & decrease in grain size
The difference between gross & net calorific values of fuel is due to the
Sensible heat carried away by the flue gases
Heat carried away by the steam from the moisture content of the fuel
Heat lost by radiation
Heat carried away by steam from the combustion of hydrogen in the fuel
The taper provided on pattern for its easy & clean withdrawal from the mould is termed as the __________ allowance.
Casting
Pattern
Draft
Distortion
Which of the following processes follows the hardening process for reducing the hardening strains & increasing the toughness of the steel part?
Anodising
Tempering
Carburising
Annealing
Identify the correct statement.
Sphlerite is zinc oxide
The first law of the thermodynamics is stated as δE = δQ - δW
Lead can be produced in a blast furnace
T. ferrooxidans is a fungus that can be used for leaching chalcopyrite
The bolt is subjected to __________ when the nut is tightened by putting the washer beneath it.
Tension
Shear
Compression
Bending & tension
Enzymes belong to the category of
Proteins
Carbohydrates
Vitamins
Fats
Closeness of packing is maximum in case of __________ crystal lattice.
Face centred
Simple cubic
Body centred
None of these
The joint for soldering is supported by binding wire made of
Mild steel
Copper
Soft iron
Stainless steel
If Reynolds number is greater than 1, then the
Viscous force is larger than the inertia force
Inertia force is larger than the viscous force
Inertia force is larger than the surface tension force
Inertia force is larger than the gravitational force
For grinding of softer materials, the grinding wheel should have __________ grain size.
Finer
Coarser
Medium
Any type of
__________ circuit is most commonly used to measure strain with the help of a strain gauge.
Ballast
Voltage balancing potentiometric
Simple current sensitive
None of these
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
Which of the following is not the commercial name of poly-methyl-methacrylate (PMMA)?
Styrofoam
Lucite
Perspex
Plexiglass
Dislocation cross-slip is difficult in those materials, which have
Large number of slip systems
High work hardening rate
Coarse grain size
Low stacking fault energy
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
__________ is not a heat treatment process.
Cyaniding
Parkerizing
Austempering
Martempering
Electrometallurgical methods of metal extraction is normally used for those metals
Whose oxide/ore is not reduced by carbon
Which fall in the category of alkali & alkaline earth metals
Which stands higher in the electrochemical series of the metal
All (A), (B) & (C)
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
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 the most suitable material of construction for the condenser tubes, where the cooling medium is brine (salty water)?
Aluminium
Copper
Titanium
Stainless steel
__________ is a non volatile film forming constituent of a paint.
Thinner
Dryer
Drying oil
None of these
While the oxy-acetylene flame produces a temperature of 3200°C, the temperature produced by oxy-hydrogen flame is about __________ °C.
1800
2000
2400
3000
Which of the following is an example of cathodic protection of metals against corrosion?
Painted steel
Galvanised iron
Case hardened steel
Lead lined reactor
Dielectric
Is an electrical insulating material
Of low resistivity is preferred
Should have high thermal conductivity
Need not defy the corrosive action of chemicals
Recrystallisation temperature of steel is __________ °C.
50
300
500
800