List of practice Questions

A 10 ml sample of wastewater is diluted with water having no BOD, to fill a 300 ml BOD bottle. The initial DO of the diluted waste water is 9.0 mg/l. If the BOD\(_5\) of the waste water sample is 60 mg/l, the final DO of the diluted waste water in mg/l, is
A coal sample having moisture content of 8.0% has unit weight 15.6 kN/m\(^3\). The dry unit weight of the sample, in kN/m\(^3\) is \(\underline{\hspace{1cm}}\). (round off to 2 decimal places)
In sound frequency analysis, the lower and upper frequencies of a 1/1 octave band are 710 Hz and 1420 Hz respectively. The centre frequency of the band in Hz is \(\underline{\hspace{1cm}}\). (round off to the nearest integer)
In Battle Environmental Evaluation System (BEES) of Environmental Impact Assessment (EIA), "air pollution'' has a Parameter Importance Unit (PIU) of 52. The Environmental Quality (EQ) score of a project with respect to air pollution was 0.8 before implementation and 0.6 after implementation. The difference in Environmental Impact Unit (EIU) is \(\underline{\hspace{1cm}}\). (round off to 2 decimal places)
A system consists of four components in parallel. Their reliabilities are 0.40, 0.60, 0.50, and 0.40. The system reliability is \(\underline{\hspace{1cm}}\). (round off to 3 decimal places)
A vehicle moving at 12 m/s stops in 15 m with constant deceleration. Assuming \( g = 10\ \text{m/s}^2 \), compute the coefficient of kinetic friction between tyres and road. (round off to 2 decimal places)
In a bord and pillar panel six shuttle cars, each of 10 tonne capacity, are deployed to transport coal produced by two continuous miners to a belt conveyor. Each shuttle car on an average carries 80% of its rated capacity and makes 7 round trips in an hour. The belt conveyor has a capacity such that the effective material cross section area is of 0.09 m$^{2$ and runs at a speed 1.1 m/s. The broken coal has a bulk density of 1.2 tonne/m$^{3}$. The ratio between the production and the capacity of the belt conveyor, in percent is}
Variance of the sum of two statistically independent random variables \(X\) and \(Y\), \( \sigma^2_{X+Y} \), is
The difference between depreciation and amortization allowances in tax calculation is that
Owning cost of a machine does NOT include
Folds are the structural features resulting from
Given impeller diameter $D$, speed of rotation $n$ and air density $\rho$, for geometrically similar fans, the fan pressure is proportional to
NONEL is used as down-the-hole initiator to
As per MMDR Act 1957, for the allocation of lease of minor minerals
In photogrammetry, the 'Tilt of a photograph' refers to the angle between the
The hydraulic sand stowing pipeline layout should be such that
For a "positive definite" square matrix, the TRUE statement is
The standard normal distribution is a
Resuing method of mining is practiced for
The equipment used for both drop cut and terrace cut in surface mining is
Surface miner does NOT have a
Induced blasting enhances production in
The measures of dispersion of a dataset are
Tricone roller bit is used with
A satellite orbits the Earth at an altitude of 700 km on the equatorial plane of the earth and it revolves in the same direction as the direction of rotation of the earth. Considering the radius of a spherical earth as 6300 km and the acceleration due to gravity as 10 m/s², the tangential velocity of the satellite in the orbit is \(\underline{\hspace{1cm}}\) km/s. (round off to 2 decimal places)