The most serious manufacturing defect from fracture toughness point of view is
Surface roughness
Pores
Spherical inclusion
Crack
Correct Answer :
D. Crack
Related Questions
Out of the following substances, one ton of __________ will store the maximum heat for a rise of 30°C in temperature.
Steel
Lignite
Water
Lime stone
__________ fluid force is not considered in the Navier-Stokes equation.
Turbulent
Viscous
Gravity
Pressure
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
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
The main constituent of bones is
CaF2
Ca3(PO4)2
CaCO3
CaCl2
Sacrificial anode method is used in the protection of pipelines which are buried underground. Sacrificial anode
Occurs higher in the electro-chemical series of metals
Is exemplified by magnesium plate
Is much cheaper than the cathodic base material to be guarded against corrosion
All (A), (B) & (C)
Often earing defects are found during deep drawing operation, because the
Surface finish of the sheet is poor
Sheet material has been given substantial spring back
Starting sheet has planer anisotropy due to its texture
Starting sheet has normal anisotropy due to its texture
Rain drops falling through atmospheric air attain limited terminal velocity, because of
Upward thrust due to air
Viscous force exerted by air
Surface tension effects of water
Force of gravity
The most important requirement for aluminium industry is the availability of cheap
Ore
Electrical power
Labour
Abundant water
Increasing the carbon content of steel
Reduces the upper shelf energy
Increasing the ductility transition temperature
Decreases brittleness
Decreases hardness
Pick out the correct statement.
Hot worked materials are subjected to annealing to remove internal stresses
Annealing of steel hardens it slightly
Normalising of a material induces stresses
Tempering of a material improves ductility & toughness but reduces hardness & brittleness
Particle nature of cathode rays is proved due to the fact that they
Travel in a straight line
Get deflected by magnetic electric field
Produce fluorescence
Heat the exposed material
Friction factor for fluid flow in pipe does not depend upon the
Pipe length
Pipe roughness
Fluid density & viscosity
Mass flow rate of fluid
Which of the following has the highest modulus of elasticity (about 7 × 106 kg/cm2)?
High speed steel
Stainless steel
Tungsten carbide
Superalloys
Which of the following is an undesirable property of slag produced during the Pyrometallurgical method of metal extraction from its ore?
High fusibility & fluidity
High thermal conductivity
Low density
High chemical activity
Fine grained steels have
High brittleness
Higher tendency to distort
High ductility
None of these
The highest stress that a material can withstand for a specified length of time without excessive deformation is called the __________ strength.
Creep
Endurance
Fatigue
None of these
Normalising does not __________ of a metal.
Improve machinability & tensile strength
Remove internal stresses
Refine the structure
Remove strains caused by cold working
Which of the following are considered applications of ultrasonic testing?
Determination of elastic constant
Detection of defects in metal
Measurement of material thickness
None of the above
Damage to metal surface by mechanical action is called
Pitting
Corrosion
Erosion
None of these
Which of the following test is used for distinguishing among dry oils, semi-drying oils and non drying oils?
Elaiden test
Reichert-Meissl value test
Hunter value test
Iodine value test
Main constituent of bone ash is
Ammonium phosphate
Calcium phosphate
Animal charcoal
Ammonium sulphate
Which of the following does not discharge the dust collected as a dry solid?
Electrostatic precipitator
Wet scrubber
Bag filter
Gravity settling chamber
If the head is doubled in & centrifugal pump, the power required will increase in the ratio of
23
23/2
25/2
21/3
In condensers used in thermal power plants, steam is normally used in shell side and cooling water on the tube side, because of the reason that
Compared to the mass flow rate of cooling water, the rate of condensation of steam is invariably smaller
Maintaining vacuum on tube side is more difficult than that on the shell side
Water velocity can be increased conveniently to increase the overall heat transfer co-efficient because of its lower specific volume compared to steam
Condenser can act as a storage unit for condensed steam
In an amorphous material, atoms defy any definite atomic structure and exist in random pattern just like in liquid. Which of the following is an amorphous material?
Tin
Lead
Zinc
Glass
For a first order chemical reaction, the concentration of the reactant decreases __________ with time.
Linearly
Exponentially
Logarithmically
Inversely
L.D. (Linz-Donawitz) converter is used in the production of
Copper
Steel
Zinc
Aluminium
CANDU type nuclear reactor using natural uranium as fuel is the extensively used nuclear reactor because of the fact that the
Specific fuel consumption is very low due to the use of heavy water
Fuel cost is much lower than that used in pressurised water or boiling water reactor
Heavy water is used both as coolant as well as moderator
Both 'b' & 'c'
Water flow in the river during flood can be categorised as the __________ flow.
Unsteady uniform
Unsteady non-uniform
Steady uniform
Steady non-uniform