A. Nickel
B. Cobalt
C. Vanadium
D. Platinum
Related Mcqs:
- The amount of water evaporated in kg per kg of fuel burnt in a boiler is called the ______________ of a boiler ?
A. Evaporative capacity
B. Evaporation efficiency
C. Thermal efficiency
D. Steam load - L.D. (Linz-Donawitz) converter is used in the production of____________________?
A. Copper
B. Steel
C. Zinc
D. Aluminium - Current employed in resistance welding ranges from ____________________ kVA/cm2?
A. 1.2 to 2.5
B. 4.5 to 6.2
C. 7.5 to 8.5
D. 10.5 to 15.5 - Fire refining process is employed in case of___________________?
A. Tin
B. Copper
C. Zinc
D. Aluminium - Which of the following mainly decides the current to be employed is arc welding ?
A. Electrode size
B. Plate thickness
C. Voltage across the arc
D. Welded portion length - The thickness of oxide film is y at time t. If K1, K2 and K3 are the temperature dependent constants, the parabolic law of oxidation is given by __________________?
A. y2 = 2k1t + k2
B. y = k1 ln (k2t + k3)
C. y = k1 t + k2
D. y = k1t3 + k2 - Volumetric composition of flue gas analysed with the Orsat apparatus is : CO2 = 12%, O2 = 8%, CO = nil, N2 = 80%. This flue gas composition indicates that_________________?
A. Pure oxygen has been used for combustion
B. Nitrogen percentage in the fuel is very high
C. Excess air has been used for combustion
D. Hydrogen is not present in the fuel - An oxidation process is accompanied with decrease in the____________________?
A. Number of electrons
B. Oxidation number
C. Number of ions
D. All A , B. & C. - _____________ is the process of coating the surface of steel with aluminium oxide, thereby imparting it increased resistance to corrosion & oxidation upto a temperature of 700°C ?
A. Veneering
B. Galvanising
C. Electroplating
D. Calorising - Plants produce carbohydrates from the CO2 present in the atmosphere by_________________?
A. Polymerisation
B. Photochemical reaction
C. Oxidation
D. None of these
