Metallic surveying tapes are made of __________ which has a low co-efficient of expansion & enough strength.
Invar
Hastelloy
Duralumin
Monel metal
Correct Answer :
A. Invar
Related Questions
Minimum thermal efficiency of a steam boiler may be around __________ percent
25
45
65
20
Unit of viscosity in CGS system is
The specific gravity of coal depends mainly on its __________ content.
Carbon
Volatile matter
Ash
Moisture
Pick out the correct statement
Jet engine can work, where there is no atmosphere
Rocket engines cannot work, where there is no atmosphere
Rocket engines carry oxygen required for the combustion in the form of oxidiser
Jet engines also carry oxidiser
The bank of tubes located at the back of the domestic refrigerators are the __________ tubes.
Refrigerant cooling
Evaporator
Condenser
Throttling
Optical activity is a/an __________ property.
Additive
Constitutive
Both (A) & (B)
Neither (A) nor (B)
Starting friction is low in case of the __________ lubrication.
Boundary
Hydrodynamic
Hydrostatic
Mixed/semi-fluid
Thermal diffusivity of a substance is proportional to (where, k = Thermal conductivity)
1/k
k
k2
1/k2
What is the percentage of chromium in 18-4-1 high speed steel?
1
4
18
23
Out of the following, which will fracture most readity, when hit with a hard hammer?
Brass
Bronze
German silver
Cast iron
Strain hardening effect in a metal subjected to cold working is due to the __________ mechanism.
Fracture
Dislocation
Slip
Twinning
__________ test determines the yield strength, Young's modulus of elasticity, percentage reduction in area & percentage elongation of a material.
Tensile
Fatigue
Impact
None of these
Alcohols are not suitable as diesel engine fuel because the cetane number of alcohols is
Very low which prevents their ignition by compression
Very high which prevents their ignition by compression
Zero
None of these
On oscilloscope screen for dynamic measurement, lissajous diagram is normally used to determine the __________ of the input signal.
Frequency
Amplitude
Damping
None of these
__________ joint is mostly used for joining pipes carrying water at low pressure.
Nipple
Socket
Union
Bell and spigot
The following thermocouple may be used for measuring temperature upto 1873°K.
Chromel-alumel
Copper-constantan
Platinum-platinum rhodium
Iron-constantan
Powder metallurgy process does not make metal powder by
Atomisation
Grinding/milling
Hammering
Electrolytic deposition
The most abundant metal present in the earth's crust is;
Iron
Copper
Titanium
Aluminium
When the wet steam is throttled but still remains wet at the exit of the throttle valve, then its temperature & dryness fraction respectively
Decreases & increases
Increases & increases
Increases & decreases
Decreases & decreases
Which of the following is an unconventional source of energy?
Thermal power
Hydroelectric power
Nuclear-fusion power
Solar power
Out of the following __________ iron has the best capability to bear sudden & excessive shocks.
White
Cast
Wrought
Pig
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
Upto the critical radius of insulation, added insulation, will
Increase the heat loss
Decrease heat loss and will have no effect beyond that
Decrease heat flux
Reduce convection heat loss compared to conduction heat less
The boiling & freezing points on a newly defined temperature scale in degree 'D' are 400°D & 100°D respectively. The temperature reading corresponding to 60°C on this new temperature scale will be equal to __________ °D.
140
180
240
280
Baffles provided on the shell side of a shell and tube heat exchanger are meant for
Providing support for the tubes
Improving heat transfer
Both 'a' & 'b'
Preventing the fouling of tubes & stagnation of shell side fluid
The emf of a Deniell cell Zn | Zn2+ || Cu2+ | Cu can be increased by
Decreasing the surface area of the electrodes
Increasing the concentration of zinc sulphate solution
Increasing the surface area of the electrodes
Increasing the concentration of copper sulphate solution
The activity co-efficient of the solute in a dilute solution
Decreases with the increase of concentration of the solute
Increases with the increase of concentration of the solute
Remains constant
Is unity at infinite dilution
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
Mild steel has __________ crystal lattice structure.
Face centred cubic (fcc)
Body centred cubic (bcc)
Orthorhombic
Cubic
Thermal equivalent of electrical power in practical calculation is __________ kcal/kWh.
746
3000
1000
550