Questions 281–290 of 300. Imported answers require independent review unless marked reviewed.

Topic practice 300 questionsPage 29 of 30

Question 30

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The areas within the contour lines of a proposed site for an overburden dump are as follows:
| Contour RL (m) | Area (m²) | | 195 | 3054 | | 180 | 3025 | | 165 | 2095 | | 150 | 2008 | | 135 | 2000 | | 120 | 1992 |
The total volume of overburden in cubic meter that could be dumped within the 120 m and 195 m contour levels is

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Question 31

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Total ore mined from a sub-level open stope of a copper deposit is measured to be 10000 tonne. The ore recovery and ore dilution during stoping are 90% and 20% respectively. The in situ Cu grade of the ore in the stope is 0.65%. The selling price of copper is Rs. 400/kg of metal. Ignoring any other metal losses in the downstream process of the ore, the revenue generated by selling the ore in Crores of rupees is

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Question 32

Open question
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The block grade model of an ore deposit is shown in the figure below.
Diagram for Mining Engineering question 32

The relationship between block value per tonne (

) in rupees and the block grade in percentage (

) is given below:

, for


, otherwise
If each square block contains 1000 tonne of material and the overall pit slope angle is

, the total value of the pit determined by the floating cone algorithm in Lakhs of rupees is

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Question 33

Open question
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A mine is being developed by bord and pillar method with a gallery size of 4.8 m × 2.4 m. The mine operates in 3 shifts per day and 6 faces are blasted per shift. The average pull per round of blast is 1.2 m and the bulk density of coal is 1.4 t/m³. If the OMS is 2.5, then the average manpower deployed in the development section per shift is

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Question 34

Open question
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Consider the following linear programming problem:
Maximize

Subject to







The maximum value of the objective function is

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Question 35

Open question
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A mining company having three mines A, B and C supplies coal to three power plants P, Q and R located close to the mines. The daily production capacities of the three mines in tonnes are 700, 1200, and 1100 respectively. The daily requirements at the power plants in tonnes are 1000, 1000, and 1000 respectively. The transportation costs in rupees per tonne is given in the matrix below:
| Mine / Power plant | P | Q | R | | A | 15 | 20 | 60 | | B | 5 | 40 | 20 | | C | 30 | 10 | 50 |
The total cost of coal transportation in rupees from the three mines to the power plants using the least-cost method is

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Question 36

Open question
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The series-parallel configuration of a system, consisting of 6 independent components A, B, C, D, E, and F with their individual reliability, is shown in the figure:
Diagram for Mining Engineering question 36

The reliability of the system is

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Question 37

Open question
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500 coal miners were randomly selected from an underground coal mine. It was found that 50 workers experienced an injury in the year 2014. The distribution of injury based on younger age group (age ≤ 40 years) and older age group (age > 40 years) generated the following cross classification table.
| Age group | Injured | Non-injured | Row total | | Younger age group | 20 | 130 | 150 | | Older age group | 30 | 320 | 350 | | Column total | 50 | 450 | 500 |
The odds of injury for the younger age group compared to the older age group is

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Question 38

Open question
MNNAT2 marksNeeds review
A bord and pillar panel is being planned at a depth of 300 m. The dimension of square pillar is 35 m centre-to-centre. The average unit weight of the overburden rock is 25 kN/m³. If the strength of the pillar is 14.0 MPa, the gallery width in m for a safety factor of 1.3 is

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Question 39

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A sandstone sample having 15% moisture content and volume of 75 cm³ weighs 180 g. If the grain density is 2.6 g/cm³, porosity of the sample in % is

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