Related Questions

Mineral matter content (M) and ash content (A) in coal are approximately related as
A M = 1.1A
B M = A
C M = 1.5A
D M = 2A
In coal washeries, three products namely the valuable product (i.e. clean/washed coal), discarded product (i.e. mineral matter) and an additional concentrated product called __________ is produced.
A Concentrate
B Tailing
C Middling
D None of these
A coal having high ratio of volatile matter to fixed carbon as compared to a coal having low ratio of volatile matter to fixed carbon
A Is less liable to spontaneous combustion on storage
B Is more difficult to ignite and produces a shorter flame
C Requires smaller combustion space and less secondary air
D None of these
Ash content in the middling coal (a byproduct of coal washeries) in India ranges between __________ percent.
A 15 to 25
B 35 to 45
C 55 to 75
D 75
Softening temperature of coal ash is a measure of the __________ of coal.
A Caking tendency
B Coking tendency
C Clinkering tendency
D Size stability
For making fly-ash building bricks, the following mix of fly-ash, sand and lime, is
A 80 : 13 : 7
B 70 : 20 : 10
C 60 : 35 : 5
D None of these
The popular notion that a tree's age can be determined by counting number of internal rings in its trunk is generally true. Howeevr, to help regulate the internal temperature of the tree, the outermost layers of wood of the Brazilian ash often →peel away when the temperature exceeds 95 degrees Fahrenheit, leaving the tree with fewer rings than it would otherwise have. So only if the temperature in the Brazilian ash's environment never exceeds 95 degrees Fahrenheit →elav eing the tree with fewer rings than it would otherwise have. So only if the reliable measure of the tree's age. Which of the following is an assumption on whish the argument above depends?
A The growth of new rings in a trees is not a function of levels of precipitation.
B Only the Brazilaian ash loses rings because of excessive heat.
C One day of temperatures above 95 degrees Fahrenheit will cause the Brazilian ash to lose one ring.
D The internal rings of all tress are of uniform thickness
During coking of coal, the ash content (percentage)
A Increases
B Decreases
C Remains constant
D None of these
Higher percentage of ash in coal meant for the production of metallurgical grade coke
A Decreases the hardness of coke
B Decreases the abrasion resistance of coke
C Causes brittleness in steel
D None of these
Degree of carbonisation of coal during coke making can be roughly judged by the __________ of the coke produced.
A Colour
B Moisture content
C Ash content
D Volatile matter

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