List of top Questions asked in GATE MN

Information on Activity-Time duration of a project is provided below. The expected project duration in weeks, is ____________. (in integer)

In a surface mine bench, overburden is removed by shovel–dumper combination. Data for the dumper is given. Minimum number of dumpers required to avoid shovel idle time (in integer) is __________.

In a bord and pillar panel, with headings of 4.4 m × 2.5 m advanced by solid blasting, the average pull per round = 1.2 m and 12 faces are blasted per day. Density of coal = 1500 kg/m$^3$. Mine works three shifts; daily employment = 330 persons. Labour productivity (OMS) in tonne (rounded off to two decimals) is __________.

The point A(7,17) in the Coward flammability diagram represents the gas composition of a sealed-off area (volume = 10000 m$^3$). Inert gas is injected so that composition moves below the LEL boundary. Minimum required inert gas volume (in m$^3$, rounded off to one decimal place) is __________.

An 8 m × 6 m × 4 m workshop has four identical luminaires at roof corners. Each is 100 W with luminous efficacy 100 lumen/W. Light is transmitted spherically with no reflections. Illumination at the centre of the floor (in lux, rounded off to two decimals) is __________.

In a health centre, the probability of ‘full occupancy’ of COVID beds for a day is 0.8. Assuming Binomial probability distribution, the probability of full occupancy exactly for 5 days in a week is __________ (rounded off to three decimal places).

Information for a drilling operation in an overburden mine is given: Volume of rock blasted per round = \(3.2 \times 10^5\ \text{m}^3\)
Number of blast holes = 100
Drill hole diameter \(D = 200\ \text{mm} = 0.2\ \text{m}\)
Length of subgrade drilling = \(8D = 1.6\ \text{m}\)
Stemming length = \(25D = 5\ \text{m}\)
Bench height = 30 m
Powder factor = \(3.2\ \text{m}^3/\text{kg}\) Find the explosive per unit charge length (kg/m), rounded to two decimals).

The shaft-top coordinates of two vertical shafts are given below. The depth of the shaft A and B are 200 m and 149 m, respectively. The downward gradient of the line joining the bottom of the two shafts in degrees, is __________. (round off to two decimal places)

For the oxygen-balanced explosive ANFO reaction \[ 3NH_4NO_3 + CH_2 \rightarrow 7H_2O + CO_2 + 3N_2 \] the amount of ammonium nitrate (in kg, rounded off to two decimals) required for 100 L of fuel oil (density 850 kg/m$^3$) is __________.

Two weightless cables of equal length and equal cross-sectional area hang from a ceiling. They are connected by a horizontal light bar of length 1.0 m. A downward force $F$ is applied at a point located $x$ meters from Cable–1. The moduli of elasticity of Cable–1 and Cable–2 are 50 GPa and 200 GPa respectively. If the deformation in both cables is equal, find $x$ (in m), rounded to one decimal place.

A circular tunnel of radius 3 m is constructed in a hydrostatic stress field of 15 MPa. The rock has modulus of elasticity $E = 5$ GPa and Poisson’s ratio $\nu = 0.25$. A uniform support pressure $p_i$ is applied at the tunnel boundary to restrict the radial deformation to 4 mm. The value of $p_i$ in MPa (rounded off to two decimals) is __________.

A bord and pillar panel initially has an extraction ratio of 0.15. After widening galleries, the extraction ratio changes to 0.25. Using the tributary area method, the percentage change in pillar stress (rounded off to two decimals) is __________.

The closest match of the scatter plot between the variables X and Y with the approximate attribute is:

A 3-point borehole extensometer is installed to identify the location of a single discontinuity plane in a hanging wall rock by measuring deformations at three locations as shown in the figure. The absolute readings of deformations measured on two different dates are listed in the table. Based on the measured data the most likely inference is

Match the semi-variogram shape with the model name and the property.

In a uniaxial compressive strength test, a rock sample of diameter 50 mm fails at an angle of $60^\circ$ as shown. If the peak load at failure is 120 kN, the normal and shear stresses on the failure plane, in MPa, are __________________ and __________________.

A coal mining company examines the option of buying two types of dumpers with the following details.

In order to minimize the operating cost, the optimum fleet of dumpers of Type-1 and Type-2, respectively are

Let $f(x)$ be a continuous and differentiable function on $[3,18]$. If $f(3) = -50$ and $f'(x) \le 20$, then the largest possible value of $f(18)$ is __________ (in integer).

The cost of a screw compressor with an estimated life of 15 years is ₹21,00,000. If the depreciation charged using the ‘sum-of-the-years-digits’ (SOYD) method at the end of the 4th year is ₹2,00,000, the salvage value (rounded off to one decimal place) is __________.