Related Questions

A flat coal seam of thickness (t) 3m is excavated and broken roof rock has completely filled the space created due to extraction as shown in the figure. If the bulking factor of roof rock is 1.2. the caving height (H) in m is
Introduction to Mining Engineering mcq question image
Where two or more seams or sections are worked in a mine, the pillars in one seam or section shall be vertically above or below the pillars. The parting left between any two such seams or sections shall not be less than "A" meters in thickness at any place. A is given by
There are 150 gearwheels in a box, out of which 112 are within the required tolerance, 21 are below and rest are above the required tolerance. If the selection is done without replacement, the combined probability of randomly selecting a gearwheel below the tolerance and then a second one above the tolerance is
A man sitting in a train is counting the pillars of electricity. The distance between two pillars is 60 meters, and the speed of the train is 42 km/hr. In 5 hours, how many pillars will he count?
Statements : All benches are desks. Some desks are roads. All roads are pillars.

Conclusions :
I. Some pillars are benches.
II. Some pillars are desks.
III. Some roads are benches.
IV. No pillar is bench.
Threshold Limit Value (TLV) is the maximum allowable concentration (i.e. safe limit) of pollutants in air. Safe limit for SO2 in air is __________ ppm.
A resistor of 10 kΩ with 5% tolerance is connected in parallel with a 5 kΩ resistor of 10% tolerance. What is the tolerance limit for the parallel network?
What will be the extraction factor of the process of extraction for the first stage of the extraction under the staged counter current process of extraction?
One Y suffered serious injuries in a railway accident. He was assisted by a surgeon, X, on the evidence of whose Y succeeded in recovering heavy damages against the Railway. Later on it was reported to the Railway that Y did not suffer so serious an injury as was made out by X who fraudulently created those symptoms. On legal advice obtained by the Railway, X was prosecuted but he was acquitted. He brought a suit against Railway for malicious prosecution.
A rectangular swimming pool is 15 meter long and 30 meter wide. A deck, with uniform width, surrounds the pool. If the total area of the pool and deck is 1050 square meter what is the width of the deck in meter?