Resistance of an electrical conductor is proportional to its (where, l = length and A = cross-sectional area of the conductor)
A
l
A2
Both 'a' & 'b'
Correct Answer :
D. Both 'a' & 'b'
Related Questions
The joint for soldering is supported by binding wire made of
Mild steel
Copper
Soft iron
Stainless steel
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
Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to __________ boiling.
Film
Nucleate
Transition
All modes of
Strain hardening effect in metals subjected to cold working is due to the __________ mechanism.
Slip
Fracture
Winning
Dislocation
__________ of austenite decreases the hardenability in steel.
Fine grains
Coarse grains
Homogeneity
Dissolved elements (except cobalt)
Optical activity is a/an __________ property.
Additive
Constitutive
Both (A) & (B)
Neither (A) nor (B)
Heat transfer by __________ is almost absent in case of fluidised bed drying operation.
Radiation
Conduction
Convection
Both (B) & (C)
Damage to metal surface by mechanical action is called
Pitting
Corrosion
Erosion
None of these
Basicity 
of the slag in Indian blast furnace is in the range of
0.7-1.0
1.1-1.4
1.5 - 1.8
2.0 - 2.5
Corona discharge is related to the operation of a/an
Induction motor
Electrostatic precipitator
Fast breeder reactor
Magneto hydrodynamic generator (MHD)
__________ property of steel increases by addition of large amount of silicon in it.
Mechanical
Machining
Magnetic
Refractory
Steam condenser tubes are made of admiralty brass, in which percentage of zinc & copper are __________ respectively.
70 & 30
30 & 70
50 & 50
90 & 10
Principal alloying element in Elinvar (used for making hair springs for watches) is
Copper
Aluminium
Nickel
Zinc
Main constituent of bone ash is
Ammonium phosphate
Calcium phosphate
Animal charcoal
Ammonium sulphate
What is the pH of distilled water?
0
1
7
14
Enzymes belong to the category of
Proteins
Carbohydrates
Vitamins
Fats
The product out from a cupola is called
Wrought iron
Pig iron
Cast iron
None of these
Energy to be supplied to the radioactive nucleus for the emission of a neutron is __________ MeV.
0.8
7.8
200
10000
Pick out the correct statement.
Materials exhibiting high elasticity obey Hooke's law
The elastic behaviour of rubber under compression is the same as its behaviour under tension
The damping capacity of a material is due to its plastic deformation
The stress required to cause plastic flow in polycrystalline material is higher as compared to monocrystalline materials due to the presence of grains of different orientations
Coating provided on the electrodes used in the arc welding is not expected to
Add alloying elements
Prevent electrode from contamination
Stabilise the arc
Provide protective atmosphere to weld
During decarburising of a plain carbon steel, the thickness of ferrite layer growth is proportional to
Time
Square root of time
Square of time
Cube of time
Theoretical volume of oxygen required for complete combustion of 1Nm3 of acetylene, in oxyacetylene welding is __________ Nm3.
0.5
1
1/3
2.5
Heat release during phase change is observed in case of a/an
Boiler
Condenser
Evaporator
All (A), (B) & (C)
Fire in fuel gas pipelines is extinguished most effectively by
Spraying water
Blanketting the area with nitrogen atmosphere
Fire fighting foam
None of these
Joining of thin foils is preferred to be done by
Gamma rays
X-rays
Microwaves
Gas welding
Lead pencil contains
Graphite
Lead sulphide
Lead
Both (B) & (C)
Breakeven point represents the condition, when the company runs under no profit no loss condition. In break even analysis, total cost comprises of fixed cost
Only
Plus variable cost
Plus overhead cost
Plus selling expenses
__________ flux is used for the extraction of metal from its self fluxing ores.
No
Acid
Basic
Neutral
Nuclear fission of one atom of uranium-235 produces the energy equivalent to about __________ MeV.
20
200
500
2000
Pick out the correct combination about the role of various additives used in polymers.
Plasticiser: increases the polymer strength
Heat stabiliser: increases the maximum service temperature
Fillers: Does not affect the property of polymer but increases its weight
Lubricants: increases the flexibility of polymers