If the head is doubled in & centrifugal pump, the power required will increase in the ratio of
23
23/2
25/2
21/3
Correct Answer :
B. 23/2
Related Questions
Powder metallurgy is used to produce
High precision components with complex cavities and sharp features
Components of large size
Porosity free components
Components of such alloys whose constituents do not form alloys readily
Large diameter reinforced cement concrete (RCC) pipes are generally joined by __________ joint.
Flanged iron
Collar
Flexible
Expansion
__________ metal is used as a bearing liner material.
Pewter
White
Babbitt
Gun
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
Cobalt - 60 is used as a source of __________ in medical therapy & industrial radiography.
X-rays
γ-rays
α-rays
β-rays
The dew point of moist air becomes __________ with decrease in its relative humidity.
Less than the wet bulb temperature
More than the wet bulb temperature
More than the dry bulb temperature
Equal to wet bulb temperature
A material being tested for endurance strength is subjected to the __________ load.
Impact
Completely reversed
Dynamic
Static & dynamic
Pick out the wrong statement.
For a pressure vessel to be classified as 'thin vessel', the ratio of wall thickness to mean radius is less than 0.1
For calculating forces and efficiency of riveted joint, either rivet diameter or rivet hole diameter is used in case of pressure vessel and in structural work
Longitudinal joint is normally made butt joint to maintain the circularity of the vessel
Maximum diameter of the opening provided in a pressure vessel, which does not require any compensation is 200 mm
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
Pick out the correct statement about the condensation.
Filmwise condensation gives a lower heat transfer rate than the dropwise condensation
Suitable coating or vapour additive is used to promote film wise condensation
If a condensing liquid does not wet the surface dropwise, even then condensation will take place on it
Reynolds number of condensing liquid is based on its mass flow rate
The dimensional formula of bulk modulus of elasticity is same as that of the
Pressure
Density
Force
None of these
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 yield point phenomenon observed in annealed low carbon steel is due to the presence of the following element.
Silicon
Carbon
Phosphorous
Chromium
During sensible cooling of air, its wet bulb temperature
Decreases but dew point remains constant
Increases but dew point remains constant
Increases & the dew point decreases
Decreases & the dew point increases
The most abundant metal present in the earth's crust is;
Iron
Copper
Titanium
Aluminium
Maraging steels derive their strength from the following mechanism:
A fine, highly dislocated and strong martensite
Fine dispersions of inter-metallic of Fe, Ni, Ti etc
Fine dispersions of alloy carbides in a ferrite matrix
Fine dispersions of 
C nucleated on dislocations in austenite
Superheating of steam is done at constant
Enthalpy
Entropy
Pressure
Volume
Which of the, following is not associated with the functioning of a petrol engine?
Compression ignition system
Spark plug
Carburettor
Otto cycle
An abrupt and sudden fall in the reading of barometer is an indication of the
Storm
Rain
Clear weather
Cold wave
The same volume of all gases is representative of their
Specific gravities
Densities
Gas characteristic constants
Molecular weights
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
Holes for riveting purposes should be preferably made by
Cutting torch
Drilling
Punching
None of these
Addition of __________ to steel does not impart hardness.
Nickel
Copper
Chromium
Silicon
With increase in __________ Knocking tendency in a spark ignition petrol engine decreases.
Supercharging
Wall temperature
Compression ratio
Engine speed
Volume of blast furnace slag is about __________ times the volume of hot metal (pig iron) of the same weight
1.5
3
5
7
Air/fuel ratio by weight for combustion of methane with theoretical quantity of air will be about
9 : 1
17 : 1
23 : 1
29 : 1
Which of the following forces does not act on a fluid at rest?
Viscous force
Gravity force
Hydrostatic force
Surface tension force
Gage pressure within a spherical droplet of a fluid is 'p'. What will be gage pressure within a bubble of the same size & of the same fluid?
p
2 p
0.5 p
0.25 p
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
Unbreakable crockeries are made from __________ polymers.
Polystyrene
Melamine
Polystyrene
Polyurethane