List of practice Questions

Water flows through a vertical sand column of cross‐sectional area 4000 mm$^2$ and length 300 mm. For a water head of 600 mm, the seepage quantity is 100 mm$^3$/min. Find the hydraulic conductivity of the sand column (mm/min), rounded to three decimal places.
The modified Lauffer diagram relates roof span, RMR and stand-up time. For a roof span of 4 m, if the RMR of the rock mass changes from 40 to 60, the stand-up time increases by a factor of ____________ (rounded off to two decimal places).
In a friction winder, the skip accelerates to a steady speed in 15 s. The torque vs. time diagram is shown. Find the deceleration time (in seconds, rounded to one decimal place).
AQI sub-index values at a station are: PM$_{2.5}$ = 180, NO$_2$ = 96, O$_3$ = 84. Find the AQI for the station (integer).
Match the drilling pattern with mining operation
The bottom section of a stoping block has dimensions 200 m $\times$ 40 m. If the modified RMR of the rock mass is 50, the appropriate method of mining on the basis of Laubscher’s chart in the figure is:
Match the machine with its component.
Which one of the following is NOT a notifiable disease as per Indian mining legislation?
If the ambient lapse rate is higher than the dry adiabatic lapse rate, the atmosphere is
Identify the WRONG statement: The application of controlled air recirculation in an underground work place can
The correct order of pavement layers for a haul road from top to bottom is
A mining company produces iron ore and sells to another company. Royalty to be paid is on the basis of
A deposit has the grade attribute $X \in [0,30]$ with a density function $f(x)$. For a cut-off grade $x_c$, the proportion of the ore in the deposit is given by
The drilling technique applicable for mineral exploration is
Match the rock with its metamorphosed form
Identify the WRONG statement: Break-even stripping ratio
A square pattern of blasting is shown in the figure. For the case of simultaneous blast, identify the zone of no fragmentation.
In the truss shown in the figure, the force in the member BD, in kN, is __________________ .
The correct vertical stress profile in the case of tributary area method for pillar design is
A sewage treatment plant (capacity 10 MLD) treats wastewater using an aerobic biological process. Inlet BOD = 100 mg/L, outlet BOD = 30 mg/L. Microbial yield = 0.5 g VSS/g BOD removed. At 80% plant capacity, the sludge production rate (in kg/day, rounded off to one decimal place) is __________.
A centrifuge processes 1000 L/h of water containing 2 g/L suspended solids. The thickened slurry leaving the centrifuge has 20 g per 100 mL of solids. If the centrifuge has 99% solids-separation efficiency, find the flow rate (in L/h, rounded to one decimal place) of the supernatant stream.
A ground level source emits 1000 g/day of SO$_2$. Wind speed = 2 m/s. Dispersion coefficients at 1000 m downwind are given. Estimate the ground-level SO$_2$ concentration (in $\mu$g/m$^3$, rounded off to two decimals) at 1000 m at the plume centerline.
The figure shows heat inflow and outflow for a waste-to-energy plant furnace. Assume:
(i) total heat loss = 3% of heat released from waste,
(ii) sensible heat of waste is negligible,
(iii) complete burning of waste.
Given waste feed rate = 70 kg/h, air heat input = 300 kcal/h,
flue gas = 90000 kcal/h, ash = 10000 kcal/h.
Find the heat content of waste (kcal/kg), rounded to one decimal place.
The value of $\displaystyle \lim_{x \to 0}\frac{(1-x)^n - 1}{x}$ is
A velocity field in Cartesian coordinate system is expressed as
\[ \mathbf{v} = x\,\hat{i} + y\,\hat{j} + p(z)\,\hat{k}, \quad \text{where } p(0)=0. \] If div $\mathbf{v} = 0$, $p(z)$ is