Opencast Mining - Study Mode

[#186] Scraper overall height is . . . . . . . .
Correct Answer

(A) 3.890m

[#187] Total number of injuries in open cast mine employing 800 persons is 16 in a year, as per the DGMS norms, the injury rate per 1000 person employed is . . . . . . . .
Correct Answer

(C) 20

Explanation

Solution: The injury rate per 1000 person employed can be calculated using the following formula: Injury rate = (Total number of injuries / Total number of persons employed) x 1000 Using the values given in the question, we can calculate the injury rate as follows: Injury rate = (16 / 800) x 1000 = 20 Therefore, the correct answer is option C, 20. The injury rate per 1000 person employed is a common metric used in occupational health and safety to measure the frequency of workplace injuries. The DGMS (Directorate General of Mines Safety) is a regulatory agency in India that sets safety standards and guidelines for the mining industry. As per DGMS norms, an injury rate of 20 or less is considered acceptable for opencast mines.

[#188] Drilling, blasting is eliminated in the following open-cast method.
Correct Answer

(D) Surface miner

Explanation

Solution: The open-cast mining method that eliminates drilling and blasting is the surface miner. Surface miners are machines that use a cutting drum to extract rock or minerals from the surface of the earth. They can selectively extract material without the need for drilling and blasting, which can reduce the environmental impact and improve safety. Option A, dozer, is a type of earthmoving equipment used for pushing soil, rocks, or other materials. Dozers are not typically used for extraction of minerals or rock. Option B, shovel, is a type of excavation equipment that uses a bucket to dig and load material. Shovels may require drilling and blasting to extract rock or minerals from the earth. Option C, dragline, is a large excavation machine that uses a bucket attached to a cable to dig and remove material. Draglines are often used in strip mining operations and may require drilling and blasting to extract rock or minerals from the earth. Therefore, the correct answer is option D, surface miner.

[#189] Hydraulic shovels which eliminate the use of . . . . . . . .
Correct Answer

(A) Wire ropes

[#190] Which is the modification of dipper shovel with a long boom and used for casting fragmented rock or earth into a dump of over burden.
Correct Answer

(B) Stripper shovel