The starting of a car takes time in winter, because the
Octane number of fuel is decreased
Fuel supply for ignition is not sufficient
Vaporisation of the fuel is decreased
Pour point of fuel decreases
Correct Answer :
C. Vaporisation of the fuel is decreased
Related Questions
The best lubricants for a machine working at high temperature & load is
Grease
Solid lubricant
Animal oils
Mineral oils
Pick out the wrong statement.
Copper is the metal having the highest electronic conductivity
Hardenability & Weldability of metals are inversely related
Covalent bonding formed by sharing of electrons is present in all semi-conductor materials
Glass transition temperature applies to 'polymers' but not to 'glasses'
Magnesium is present in
Haemoglobin
Chlorophyll
Hypo solution
None of these
The noble metals
Are exemplified by Na, K and Li
Do not resist corrosion very strongly
Are the lowermost in the electro-chemical series of metals
None of these
If the demand for an item is trebled and the order cost is reduced to one third, then the economic order quantity
Is trebled
Remains unchanged
Decreases by a factor of 3
Decreases by a factor of 1/3
__________ temperature remains constant during adiabatic saturation process of unsaturated air.
Dew point
Dry bulb
Wet bulb
None of these
Surface tension of a liquid
Is due to intermolecular forces of cohesion
Decreases with rise in temperature
Is responsible for the spherical shape of an isolated liquid drop
All (A), (B) & (C)
Steel produced from phosphatic iron is __________ in nature.
Malleable
Ductile
Brittle
Tough
Which of the following equipments is used for liquid dispersion?
Packed column
Venturi scrubber
Bubble cap plate column
Wetted wall column
A compact estimate about the amount of materials handling between various work stations is obtained from the
Gantt chart
Bin chart
String diagram
Travel chart
Constituents of stellite are
Zinc, copper & nickel
Cobalt, chromium & tungsten
Zinc, aluminium & nickel
Nickel, cobalt & vanadium
Which of the following is not used as a bearing material?
Copper-lead alloys
Babbitts
Bronzes
Cermets
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
Matte smelting is used in the extraction of
Lead
Zinc
Aluminium
Copper
Alloying elements present in Haynes stellite, which has superior performance than high speed steel, are:
Nickel, cobalt & chromium
Tungsten, chromium & cobalt
Manganese, chromium & cobalt
Tungsten, molybdenum & nickel
Density in the solid state is slightly less than that in its liquid state, in case of
Carbon dioxide
Water
Mercury
None of these
__________ cannot increase the fatigue strength of a material.
Grain refining
Grain coarsening
Surface hardening
Shot peening
Exposure to __________ accelerates the degradation of plastics.
Ultraviolet radiation
High atmospheric temperature
High ambient temperature
Damp atmosphere
Change in volume of metals from absolute zero temperature to their melting points is
Almost same for all metals
Different for different metals
Less for low melting point metals
Less for high melting point metals
The most important consideration, while designing the refrigeration system of an aircraft is that the refrigeration system
Is as light as possible
Has very high C.O.P.
Employs minimum quantity of refrigerant
Consumer minimum horse power
Which of the following has the highest modulus of elasticity (about 7 × 106 kg/cm2)?
High speed steel
Stainless steel
Tungsten carbide
Superalloys
Faraday's law of electrolysis is related to the
Cation speed
Atomic number of the cation
Equivalent mass of the electrolyte
None of these
A reduction in thermal resistance during heat transfer does not occur in the
Convection heat transfer by stirring the fluid and cleaning the heating surface
Conduction heat transfer by reduction in the material thickness and increase in the thermal conductivity
Radiation heat transfer by increasing the temperature and reducing the emissivity
None of these
With increase in temperature, the electrical conductivity of a __________ decreases.
Semi-conductor
Metal or alloy
Dielectric
None of these
Out of the following, maximum temperature drop for a given heat flow & for the same thickness will be in the case of
Steel
Glass wood
Copper
Fireclay bricks
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
For dynamic strain measurement, the Wheatstone bridge used is of __________ type.
Voltage sensitive null
Voltage sensitive deflected
Current sensitive deflected
None of these
Two solutions A1 & A2 have pH value of 2 & 6 respectively. It implies that the solution
A1 is more alkaline than solution A2
A1 is highly acidic
A2 is very slightly acidic
Both (B) & (C)
Dielectric
Is an electrical insulating material
Of low resistivity is preferred
Should have high thermal conductivity
Need not defy the corrosive action of chemicals
A metal having a Poisson's ratio = 0.3 is elastically deformed under uniaxial tension. If the longitudinal strain = 0.8, then the magnitude of thickness strain is
-0.8
0.8
+0.08
-0.24