A. 2-5
B. 18-20
C. 12-15
D. 6-12
Related Mcqs:
- Electrolytic reduction cell used for conversion of calcined Al2O3 to Al is a carbon lined furnace operating at 800-900 °C. The purpose of electric current supplied to the furnace is to___________________?
A. Achieve very high purity of aluminium (99.9%)
B. Keep the electrolyte in liquid condition by the generation of heat
C. Electrolytically dissociate alumina
D. Both B. & C. - Maximum permissible sulphur content in steel is ______________ percent ?
A. 0.015
B. 0.055
C. 0.505
D. 0.805 - The minimum carbon content in steel should be ____________________ percent for it to respond to a hardening treatment ?
A. 0.2
B. 0.4
C. 0.6
D. 0.8 - Iron content in Indian iron ore is about _________________ percent?
A. 80-85
B. 60-65
C. 40-45
D. 20-25 - Maximum change in the hardness of martensite occurs in the carbon content range of _____________ percent in steel?
A. 0.01 to 0.10
B. 0.2 to 0.4
C. 0.5 to 0.7
D. 0.8 to 1.0 - Use of economiser in a boiler plant reduces the fuel consumption for steam generation by about _______________ percent ?
A. 1
B. 10
C. 30
D. 50 - The excess air required for the combustion of pulverized coal is of the order of about _______________ percent ?
A. 5
B. 15
C. 30
D. 45 - High relative humidity decreases the evaporative process and as the temperature is increased, the relative humidity decreases. The comfort range for human body is the ambient temperature of 22 to 27°C with relative humidity ranging from _______________ percent ?
A. 5 to 10
B. 15 to 25
C. 45 to 50
D. 75 to 80 - A solid aluminium ball, when quenched in a water bath maintained at 40°C, cools down from 550°C to 450°C in 20 seconds. The expected temperature of the ball after next 20 seconds may be about ____________________ °C?
A. 370
B. 340
C. 320
D. 300 - Lead is poured into the joint between two _______________ pipes ?
A. Mild steel
B. Concrete
C. Cast iron
D. Asbestos cement
