List of top Mining Engineering Questions

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. 

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: