Related Questions

Eutectoid reaction for iron-carbon system occurs at a temperature of __________ °C.
A 597
B 959
C 1147
D 1493
In process annealing, the hypo eutectoid steel is
A Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
B Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
C Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
D Heated below or closes to the lower critical temperature and then cooled slowly
In a hardening process, the hypo-eutectoid steel is
A Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
B Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
C Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
D Heated below or closes to the lower critical temperature and then cooled slowly
An eutectoid steel consists of
A Wholly pearlite
B Wholly austenite
C Pearlite and ferrite
D Pearlite and cementite
Steel with __________ carbon is known as hypo-eutectoid steel.
A 0.8%
B Below 0.8%
C Above 0.8%
D None of these
Eutectoid steel contains following percentage of carbon
A 0.02%
B 0.3%
C 0.63%
D 0.8%
Eutectoid composition of carbon steel at room temperature is
A Cementite
B Pearlite
C Martensite
D Ferrite
A chemical reaction occurs when the energy of the reacting molecules is __________ the activation energy of the reaction.
A Less than
B Equal to
C More than
D Equal to or more than
A chemical reaction occurs, when the energy of the reacting molecules is __________ the activation energy of reaction.
A Less than
B Equal to
C More than
D Equal to or more than
Overall rate of reaction in a heterogenous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually __________ the concentration of catalyst, if it does not entail a chain mechanism.
A Proportional to
B Independent of
C Inversely proportional to
D Proportional to the square of

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