List of top Questions asked in GATE MN

In a sublevel stope, a ringhole blast round is designed for winning 2500 tonne of ore with 8.0% metal content. The blast results into breakage of 90.0% of the design blast round. Overbreak of 250 tonne wallrock with 0.5% metal content dilutes the blasted ore. The total metal content, in tonne, considering 95% recovery of the blasted muck from the stope, is:
A continuous miner serves two shuttle cars of 12 tonne capacity each. Shuttle cars I and II operate with a total cycle time of 12 minutes and 15 minutes respectively, which includes loading time of 8 minutes for each car. The production rate of the continuous miner, in tonne/hour, is:

A constant feed of 400 mL/s is maintained by a Xanthate column of height H as shown in the figure. The outlet cross section area is \(1.0 \times 10^{-4} \, {m}^2\). The acceleration due to gravity is \(10 \, {m/s}^2\). Neglecting friction and other losses, the value of H, in cm, is (rounded off to 2 decimal places): 


 

Based on the theodolite survey for a closed traverse PQRS, the following bearings are observed for the sides of the traverse.

The interior angles at P and R respectively are:

A fixed quantity of air needs to be sent through a cross section, as shown in the figure. The perimeter of the cross section is 20 m. The radius (\(r\)) of the semicircle, in m, to minimize the air velocity through the section is: 


 

A ground reaction curve (GRC) of a 3 m radius unlined circular tunnel is shown in the figure. The tunnel is supported by 300 mm thick shotcrete lining. The uniaxial compressive strength (\( \sigma_c \)), modulus of elasticity (\( E_c \)) and Poisson’s ratio (\( \nu \)) of shotcrete material are 20 MPa, 15 GPa, and 0.25 respectively. The maximum capacity (\( p_{{max}} \)) of the lining and its stiffness (\( k \)) are given as: \[ p_{{max}} = \frac{1}{2} \sigma_c \left( 1 - \frac{(a - t)^2}{a^2} \right) \] \[ k = \frac{E_c (a^2 - (a - t)^2)}{(1 + \nu)\left[(1 - \nu) a^2 + (a - t)^2\right]} \] where \( a \) = radius of the unlined tunnel and \( t \) = thickness of the lining. If the lining is constructed after 5 mm radial deformation, the support reaction is best represented by the line shown in the figure. 

A triaxial test on a sandstone sample is conducted at a confining pressure of 10 MPa. The elastic axial and volumetric strains at axial stress of 50 MPa are recorded to be \( 4.2 \times 10^{-3} \) and \( 2.0 \times 10^{-3} \) respectively. The modulus of elasticity, in GPa, and Poisson’s ratio of the sample, respectively are closest to:

Following information are given for three mines of a company receiving explosives from three suppliers. 

Considering the initial basic feasible solution of this transportation problem, using North-West corner method, the transportation cost of explosives supplied to the company, in Rs., is

Match the type of deposit with the corresponding process of formation: 


 

The relevant information on metal extraction from a copper mine are given below: Selling price of copper (Rs./kg) = 900
Mining cost (Rs./tonne of ore) = 500
Processing cost (Rs./tonne of ore) = 2000
Overall recovery of copper metal (%) = 70
Ignoring all other costs, the breakeven cutoff grade of copper, in %, is:
If the in-situ density of coal is 1320 kg/m\(^3\) and the density of blasted coal is 952 kg/m\(^3\), the swell factor is:

In a bord and pillar panel, the following data are obtained: 
Number of blasting rounds per shift: 8 
Face dimension (m × m): 4.2 × 2.5 
Average pull (m): 1.2 
Specific gravity of coal: 1.4 
Manpower per shift: 100 
The OMS (output per manshift) of the panel, in tonne, is __________ (rounded off to 2 decimal places)}

In a ventilation network, three airways with resistances of 4.0 Ns\( ^2 \)m\( ^{-8} \), 6.25 Ns\( ^2 \)m\( ^{-8} \) and 9.0 Ns\( ^2 \)m\( ^{-8} \) are connected in parallel.

The equivalent resistance of the network in Ns\( ^2 \)m\( ^{-8} \) is _________ (rounded off to 2 decimal places)}

The unadjusted RMR of a tunnel roof is 64. A single joint set exists in the roof as shown in the figure. 

Using the abridged RMR table for adjustment orientation, the RMR is _______ (in integer)
 

The box plot of a data set is shown below. 

The interquartile range of the data set is _______ (in integer).

An HMX explosive having Velocity of Detonation (VOD) of 10500 m/s is tested by D'Auriche method with a detonating fuse of VOD 7000 m/s, as shown in the figure. The impression mark on the lead plate will be obtained at a distance \(L\), in m, from the midpoint of the fuse, is: 

 


 

In a shovel dumper combination, the loading time of a dumper is 3 minutes. The shovel serves 8 dumpers. If the cycle time of a dumper, including its loading time, is 22 minutes, the waiting time of a dumper, in minutes, is:
As per CMR 2017, haulage ropes shall be recapped once at least in every:

Pressure head characteristic of a mine fan and a mine characteristic curves are shown in the figure below: 


Match the points with their corresponding nomenclatures

The chemicals used in a foam type fire extinguisher are

The figure below shows four profiles of the environmental lapse rate. Given that the dry adiabatic lapse rate is \( -10^\circ {C/km} \), the atmosphere is highly unstable for the profile:


 

Match the source of error with the corresponding correction in surveying with steel tape.


 

Three frictionless pulleys with rope attachment are in a static equilibrium as shown in the figure. The mass \( m_1 \) and \( m_2 \), in kg, respectively are: 


 

In a Brazilian test, the front view of a homogeneous rock sample is shown in the figure. The failure initiates at the point, where the rock sample is subjected to stress. The failure initiates at the point marked as: 


 

The major (\( \sigma_1 \)) and minor (\( \sigma_3 \)) principal stresses and the maximum shear stress (\( \tau_{{max}} \)) are related as \( |\tau_{{max}}| = \sigma_1 = - \sigma_3 \). The magnitude of normal stress on the plane where \( \tau_{{max}} \) acts is: