List of top Mining Engineering Questions

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: 

Match the following

In the context of mine planning, match the following:

The inventory pattern shown in the figure does not represent the following: