Out of the following, the lowest packing of atoms exists in __________ crystal lattice structure.
Hexagonal close, packed (hcp)
Face centred cubic (fcc)
Body centred cubic (bcc)
Simple cubic
Correct Answer :
D. Simple cubic
Related Questions
Pick out the wrong statement.
Seam welding, projection welding & spot welding are the classification of electrical resistance welding
Electrode tip in spot welding is of copper and the tip diameter should be equal to t (where, t = plate thickness to be welded)
In spot welding, two pieces to be joined are overlapped and placed between two electrodes
Mild steel sheet cannot be spot welded
Evaporative cooling process employs a combination of cooling and humidification in which the
Sensible heat is added
Sensible heat is removed and the latent heat is added
Latent heat is removed
Sensible heat is added and latent heat is removed
Internal energy of a gas obeying Van-Der- Waals equation of state, [p + (a/v2)] (V - b) = RT, depends upon its
Pressure & temperature
Pressure & specific volume
Temperature & specific volume
Temperature only
Vernier calipers cannot be used to measure the
I.D. & O.D. of the shaft
Thickness of parts
Depth of holes
Clearance between two mating surfaces
The pressure outside a bubble/droplet of liquid is __________ the internal pressure.
Greater than
Less than
Equal to
Unpredictable; depends on the bubble size
Out of the following, which will fracture most readity, when hit with a hard hammer?
Brass
Bronze
German silver
Cast iron
Diamagnetic materials
Are magnetised by eddy currents only
Are non-magnetic and cannot be magnetised
Are magnetised in direction opposite to the magnetic field
Can be magnetised in one direction only
What is the value of included angle of a triangular notch for maximum discharge?
30°
60°
90°
120°
Increasing the carbon content of steel
Reduces the upper shelf energy
Increasing the ductility transition temperature
Decreases brittleness
Decreases hardness
When the wavelength of incident X-rays increases, the angle of diffraction
Decreases
Increases
Remain constant
Shows no systematic variation
Which of the following is resistant to the action of both heat & chemicals?
Borosilicate glass
Silica glass
Soda lime glass
None of these
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
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
Consideration of the creep is the most important in case of the
Blades of gas turbine
Piston of an I. C. engine
Flywheel of steam engine
Cycle chain
Fatigue limit improvement by over stressing the metal by successively increasing the load is called coaxing. In fatigue failure, the material fails
Below the yield point
Above the yield point
Below the elastic limit
At the elastic limit
Pick out the wrong statement.
Both annealing and normalising release the internal stresses of the material besides improving the mechanical properties
Low carbon steel does not respond to the heat treatment for hardening of the material, hence it is subjected to case hardening or surface hardening processes like cyaniding, carburising, nitriding etc., which produces high carbon outer layers resulting in increase of surface hardness
Induction hardening and flame hardening techniques are also used for surface hardening
Martempering of a material is a hardening process
Saturated steam at a pressure of 25 kg/cm2 is throttled to attain 5 kg/cm2. Then the outcoming steam will be
Wet
Saturated
Superheated
None of these
The ratio of thermal & electrical conductivity is same for all the metals at the same temperature; and at around room temperature, this ratio is proportional to(where, T = absolute temperature, °K)
T
1/T
T2
1/T2
Plastics as a material of construction suffer from the drawback of low
Machinability
Density
Strength
Plastic deformation
Identify the correct statement with reference to the extractive metallurgy of aluminium.
The electrolyte consists of molten Na3AlF6 with approximately 1 to 8% Al2O3
Approximately 80% of the aluminium deposited on the cathode comes from cryolite
Sodium is deposited along with aluminium, but is immediately vaporised
Anode effect sets in when the cryolite concentration goes below 40%.
Angular displacement can be measured suitably by a
Shaft encoder
Linear variable differential transducer (LVDT)
Stroboscope
Tachometer
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
Which of the following mainly decides the current to be employed is arc welding?
Electrode size
Plate thickness
Voltage across the arc
Welded portion length
Out of the following, the most malleable material is
Copper
Aluminium
Wrought iron
Lead
Fatigue resistance of a material is measured by the
Elastic limit
Ultimate tensile strength
Young's modulus
Endurance limit
Pick out the wrong statement.
Complete unity of command exists in a line organisation
Line organisation is net suitable for expansion and growth of an industry
In line and staff organisation, line executes and staff directs
None of these
For preparation of porous bearings by powder metallurgy, preferred particle shape is
Spherical
Nodular
Irregular
No preferred shape
__________ metal is used as a bearing liner material.
Pewter
White
Babbitt
Gun
Friction factor for fluid flow in pipe does not depend upon the
Pipe length
Pipe roughness
Fluid density & viscosity
Mass flow rate of fluid
Thermal equivalent of electrical power in practical calculation is __________ kcal/kWh.
746
3000
1000
550