Which of the following is an example of stress corrosion?
Season cracking of brass
Caustic embrittlement of steel
Both (A) & (B)
Neither (A) nor (B)
Correct Answer :
C. Both (A) & (B)
Related Questions
Which of the following rays has the least wavelength?
Ultraviolet rays
Infrared rays
Cosmic rays
X-rays
Which of the following is an unconventional source of energy?
Thermal power
Hydroelectric power
Nuclear-fusion power
Solar power
With increase in temperature, the surface tension of water
Increases
Decreases
Remain constant
Increases linearly
Diffusion co-efficient of a metal in a solid solution depends upon its
Composition
Temperature
Both (A) & (B)
Neither (A) nor (B)
__________ remains constant during the adiabatic cooling of moist air.
Wet bulb temperature
Dry bulb temperature
Relative humidity
Specific humidity
Non-ferrous alloys used for making cutting tools need not have high
Abrasion resistance
Toughness
Red hardness
Cutting speed
Half life of a radioactive isotope corresponds to the time required for half of the __________ to decay.
Atoms
Neutrons
Nucleons
Electrons
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
Though tin occurs lower than iron in the electrochemical series, yet it is coated on steel for corrosion protection, because of its
Lower cost
Abundant availability
Resistance to vegetable acids as the tin plate are commercially used in 'canning' industry
None of these
'Cryogenics' is concerned with the generation & use of low temperature in the range of
0°K to 123°K
0°C to - 123°C
0°C to - 273°C
0°K to 273°K
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'
Consumable electrodes are used in the __________ welding.
Gas
Arc
Thermit
Resistance
Thermodynamic cycle involved in the working of a thermal power plant is the __________ cycle.
Joule
Carnot
Rankine
Brayton
Pick out the wrong conversion of absolute & kinematic viscosities.
1 stoke = 1 cm2/sec
1 N.sec/m2 = 10 paise
1 stoke = 1 m2/sec
1 m2/sec = 104 stokes
Larger length & diameter water pipes are made by
Electrical resistance welding
Die casting
Semi-centrifugal casting
Continuous casting
Brinell Hardness Number (BHN) for talc is approximately in the range of
1-5
20-30
100-150
200-250
__________ property of steel increases by addition of large amount of silicon in it.
Mechanical
Machining
Magnetic
Refractory
Thermal efficiency of an internal combustion engine is around __________ percent.
8
35
65
80
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
Melting point & boiling points of liquid oxygen are respectively - 218.8°C & - 183°C, while the same for liquid nitrogen is - 210°C & - 195.8°C respectively. The difference in melting points of liquid oxygen & liquid nitrogen is not equal to 8.8
°C
°F
°K
°R
A form of stress corrosion failure termed as 'season cracking' is generally observed in
Thermosetting polymers
High carbon steels
Brasses
Borosilicate glasses
Heat transfer by __________ is almost absent in case of fluidised bed drying operation.
Radiation
Conduction
Convection
Both (B) & (C)
For preparation of porous bearings by powder metallurgy, preferred particle shape is
Spherical
Nodular
Irregular
No preferred shape
Thermit welding uses the following energy source.
Electrical energy
Chemical energy
Energy of high velocity electrons
Heat generated by friction
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
The highest stress that a material can withstand for a specified length of time without excessive deformation is called the __________ strength.
Creep
Endurance
Fatigue
None of these
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
Inertial forces are obtained, when the elastic forces are multiplied by __________ number.
Mach
Froude
Reynolds
Euler
Pick out the wrong statement about nucleate boiling.
Bubble generation is by expansion of entrapped gas/vapour at small cavities in the surface
Surface temperature is greater than the saturation temperature of the liquid
Heat transfer from the surface of the liquid is less than that in film boiling
The temperature is less than that of film boiling
The product out from a cupola is called
Wrought iron
Pig iron
Cast iron
None of these