A. Temperature is low
B. Atmospheric pressure is low
C. Atmospheric pressure is high
D. None of these
Related Mcqs:
- Other parameters remaining same, the recrystallisation temperature of an alloy is lowered, when_________________?
A. Strain rate is increased
B. Grain size is increased
C. Prior cold deformation is increased
D. Not affected by any of the above parameters - Corrosion rate cannot be lowered by reducing the ________________ of the corroding medium?
A. Concentration
B. Velocity
C. Temperature
D. None of these - The most detrimental impurity in high pressure boiler feed water is ___________________?
A. Suspended salt
B. Dissolved salt
C. Silica
D. Turbidity - Heat transfer to the water wall in a high pressure water wall type boiler furnace is mainly by_________________?
A. Conduction
B. Convection
C. Radiation
D. Both A. & B. - 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 ?
A. 140
B. 180
C. 240
D. 280 - The burnout heat flux in the nucleate boiling regime is not a function of the_________________?
A. Liquid density
B. Vapour density
C. Temperature difference
D. Heat of evaporation - Pick out the wrong statement about nucleate boiling ?
A. Bubble generation is by expansion of entrapped gas/vapour at small cavities in the surface
B. Surface temperature is greater than the saturation temperature of the liquid
C. Heat transfer from the surface of the liquid is less than that in film boiling
D. The temperature is less than that of film boiling - 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 ?
A. °C
B. °F
C. °K
D. °R - Principal alloying elements of cast tool alloys which have very high wear resistance & high temperature strength are ?
A. Cobalt, chromium & tungsten
B. Cobalt, chromium & nickel
C. Molybdenum, tungsten & chromium
D. Cobalt, zirconium & molybdenum - _______________ is the hardest oxide and is hence used where high wear resistance at high temperature is required?
A. Beryllium
B. Zirconia
C. Alumina
D. Magnesia
