Match the wire rope types with their corresponding cross-sectional diagrams.
Match the following sampling patterns with the corresponding sampling types.
| Sampling Pattern | Sampling Type |
|---|---|
| P | 1 Regular |
| Q | 2 Biased |
| R | 3 Stratified random |
| S | 4 Random |
A rock sample has coefficient of thermal diffusivity m²/s, specific heat 900 J/(kg ℃) and density 2600 kg/m³. The coefficient of thermal conductivity of the rock sample in W/(m ℃) is ______ (round off to 1 decimal place).
The selling price of one rock bolt (in Rs.) is given as, , where is the number of bolts produced. The manufacturing cost of rock bolts has a fixed component of Rs. 15000, and a variable component of Rs. 100 per bolt. The minimum break-even production, in number of rock bolts, is ______ (round off to 1 decimal place).
Two underground mines are separated by a horizontal coal barrier of 60 m thickness. One mine is inundated, whereas the other mine has a blind heading of dimensions 4.0 m wide and 2.5 m height terminating at the barrier. The overall in-situ shear strength of the coal mass is 500 kPa. Assume that the failure mode is in shear. At a factor of safety of 10, the maximum water head that can be withstood by the coal barrier, in m, is ______ (round off to 1 decimal place).
Air enters from ambient atmosphere into a level duct of uniform cross-section area 0.2 m² at a flow rate of 2.0 m³/s and density of 1.2 kg/m³. The entry shock loss factor is 1.0 and the resistance of the duct per meter length is 1.0 Ns²/m⁸. The static pressure measured at a distance of 20 m from the duct entrance in Pa, is ______ (round off to 1 decimal place).
A sealed-off area air sample consists of 16.0% O₂, 3.0% CO₂, and the rest is N₂. Assume that the standard composition of atmospheric air is 21.0% O₂ and 79.0% N₂. The percentage of blackdamp in the air sample is ______ (round off to 2 decimal places).
A diesel loader produces 60 l/s of exhaust fumes containing 5000 ppm of CO. The incoming air has 10 ppm of CO. The minimum amount of air flow in m³/s that is needed at the loader to dilute CO to a permissible level of 50 ppm is ______ (round off to 1 decimal place).
An underground copper mine sends 2500 tonnes of ore per day to the concentrator plant having an average grade of 1.2% Cu. The plant produces concentrate of 25.0% Cu with a recovery of 93.0%. The solids portion of tailings generated from the plant per day in tonnes is ______ (round off to 1 decimal place).
For a development heading, the blasting parameters are
Cross-section: 6.0 m × 5.0 m
Total number of holes: 72
Number of trimmer holes: 30
Depth of each hole: 3.5 m
Charge per hole (except trimmers): 3.5 kg
Charge per trimmer hole: 1.8 kg
Pull per round: 90% of hole depth
The powder factor for the development round in m³/kg is ______ (round off to 2 decimal places).