Mining Engineering
GATE MN year:2025 PYQs
Build your understanding with focused practice from past exam papers.
Questions 51–60 of 65. Imported answers require independent review unless marked reviewed.
Question 51
Open questionMNNAT2 marksNeeds review
A longwall panel is to be developed in a flat seam at a depth of H m. The surface subsidence profile (s) of the area with the horizontal distance x is estimated as
where, S_ is the maximum subsidence at the centre of the panel, x is measured from the inflection point. The value of x is negative towards the panel centre and positive towards the panel boundary.
The ratio between the critical width of the panel and the depth is_____ (rounded off to 2 decimal places).
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 52
Open questionMNNAT2 marksNeeds review
The percent Fe content of a random sample consisting of five observations is shown.
62 | 64 | 63 | 60 | 61
If mean grade of the stockpile is estimated using the above data, the standard error of mean grade, in %, is _____ (rounded off to 3 decimal places).
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 53
Open questionMNNAT2 marksNeeds review
In a bord and pillar panel, a square pillar of size 35 m × 35 m (centre to centre) is extracted to form four equal square-shaped stooks as shown. The width of each gallery and crosscut is 5 m. The height of the working seam is 3 m. The reduction in safety factor after pillar splitting by using Bieniawski’s pillar strength formula, in %, is____ (rounded off to 2 decimal places)
Bieniawski’s pillar strength formula,
; where,
= strength of 0.9 m^3 of coal block,
= pillar width and
= mining height

Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 54
Open questionMNNAT2 marksNeeds review
A five-member truss system is shown in the figure. The maximum vertical force P in kN that can be applied so that loads on the member CD and BC do NOT exceed 50 kN and 30 kN, respectively is________ (rounded off to 2 decimal places).

Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 55
Open questionMNNAT2 marksNeeds review
The characteristic polynomial of a third order matrix, A, is given by
If one of the eigen values of A is 1, then sum of the other two eigen values is ______ (in integer)
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 56
Open questionMNNAT2 marksNeeds review
The directional derivative of a function
at the point P (3, 4, 5) in the direction vector
is___ (rounded off to 1 decimal place)Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 57
Open questionMNNAT2 marksNeeds review
Average noise level at a working place is 80 dB(A) for the first 10 minutes and 60 dB(A) for the next 30 minutes. The energy equivalent continuous noise level at the place for the entire period of 40 minutes, in dB(A), is_____ (rounded off to 2 decimal places)
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 58
Open questionMNNAT2 marksNeeds review
The area bounded by the curves,
, and
is ___ (rounded off to 3 decimal places)Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 59
Open questionMNNAT2 marksNeeds review
Data from a borehole log with collar elevation at 590 mRL are given below. Composite grade is calculated using cores of 5 m above and below the reference bench at 580 mRL. The composite grade, in %, is ___ (rounded off to 1 decimal place)
Sequence of cores (top to bottom) | Core length (m) | Grade (%) |
|---|---|---|
1 | 3.0 | 40 |
2 | 3.0 | 42 |
3 | 2.0 | 41 |
4 | 3.0 | 43 |
5 | 2.0 | 42 |
6 | 3.0 | 41 |
7 | 3.0 | 44 |
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 60
Open questionMNNAT2 marksNeeds review
The information of a mining project for a life of three years is given below:
| Year 0 | Year 1 | Year 2 | Year 3 |
|---|---|---|---|---|
Revenue (Crore Rupees) | | 200 | 300 | 400 |
Capital cost (Crore Rupees) | 300 | | | |
Operating cost (Crore Rupees) | | 30 | 40 | 35 |
Applicable tax rate = 30 %
Discount rate = 10 %
If straight line depreciation with zero salvage value is applicable, the NPV, in Crore Rupees, is ____ (rounded off to 2 decimal places)
Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer