Mining Engineering
GATE MN format:nat PYQs
Build your understanding with focused practice from past exam papers.
Questions 161–170 of 300. Imported answers require independent review unless marked reviewed.
Question 39
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For a dumpy level, the bubble tube has sensitivity of 40″ for one division. While taking a staff reading at a distance of 60 m, the bubble is out of centre by 2 divisions. The error in staff reading in mm is ______. [round off to one decimal place]
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On an old plan of scale 1:100, leasehold area of a mine is now measured as 802 cm² using a planimeter. The plan is found to have shrunk, such that the original line of 10 cm is now measured as 9.8 cm on the plan. True lease hold mine area, in m², is ______. [round off to the nearest integer]
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CO is released from a point source on a level ground at a rate of 25 g/s. The average wind speed is 5 m/s. The dispersion coefficients are 150 m and 200 m in horizontal and vertical directions, respectively, at a receiver station located on the ground along the downwind direction. Assuming the plume follows Gaussian dispersion model, the concentration of CO, in μg/m³, at the station is ______. [round off to 2 decimal places]
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Assume that COVID-19 growth rate of number of infections per day (c) in a certain population is represented by the following differential equation.
Here, t stands for time in days. Time taken for the number of infections per day to double, in days, is ______. [round off to the nearest integer]
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 43
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Ore is hoisted from 620 m depth using a single skip of 7 tonne pay load. The skip winding system has constant acceleration/deceleration of 1 m/s² and a constant speed of 10 m/s. The skip loading time and unloading time are 120 s and 60 s, respectively. Considering the overall utilization of the skip as 70 %, the maximum daily capacity of the winding system, in tonne, is ______. [round off to the nearest integer]
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In an analysis of fragmented blast muck, the mean fragment size is found to be 60 cm with uniformity index of 1.25. Considering Rosin-Ramler equation, the cumulative mass fraction, in percent, to pass the grizzly screen size of 100 cm is ______. [round off to 2 decimal places]
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A single-acting reciprocating ram pump, while running at 120 rpm, delivers water at a rate of 10 litres per second. Considering the ram diameter is 150 mm and stroke length is 300 mm, the volumetric efficiency of the pump, in percent is ______. [round off to one decimal place]
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In a sand stowing arrangement, the slurry has a sand concentration of 35% by volume. The specific gravity of sand grain is 2.6. The concentration of sand by weight, in percent, in the slurry is ______. [round off to one decimal place]
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In a surface mine, third bench from the pit bottom is blasted, as shown in the figure.
The width, height and slope angle of each bench are 8 m, 6 m, and 80°, respectively. A fly rock is projected at an angle of 45° with the horizontal with initial velocity, v. If the acceleration due to gravity is 10 m/s² then the minimum velocity (v) in m/s required for the fly rock to reach just beyond toe of the pit slope is ______. [round off to 2 decimal places]
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Injury experience is studied in an underground coal mine with a random sample of 132 workers. The results of the study are tabulated below.
| Injured | Non-injured | Total workers |
|---|---|---|---|
Roof-bolter operators | 13 | 12 | 25 |
Loader operators | 35 | 72 | 107 |
Total workers | 48 | 84 | 132 |
The odds ratio of experiencing an injury by the roof-bolter operators when compared to the loader operators is ______. [round off to 2 decimal places]
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