GATE MN 2018 Paper 1 — page 17

Questions 49–51 of 65. Imported answers require review unless explicitly marked reviewed.

In a sublevel stope, 20 m high excavation is made with ring drilling in a 6 m wide orebody. In an effective shift time of 6 hrs, three rings are blasted resulting in 9 m extraction length. LHDs of 5.0

bucket capacity and cycle time of 5 minutes are used for ore transportation. The number of LHDs required for this operation is _________________.

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A coal seam lying at a depth of 200 m is developed by bord and pillar method. Pillars are 30 m centre to centre with a gallery width of 4 m. Unit weight of the overlying strata is 28

. If the pillar strength is 9.32 MPa, the factor of safety of pillar is ___________.

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Following information about a longwall retreating panel is given. Panel length = 1800 m Face length = 150 m Depth of web = 0.6 m Shearer travels at a speed of 1.5 m/min along the face. Each cutting cycle requires a non-operational time of 2 h 20 min. The panel is fully extractable. The number of working days required to extract the panel is ______________.

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2018 · Paper 1

Question 39

Question 40

Question 41