Jack hammer does NOT contain

At the inlet of a mine roadway, the dry and wet bulb temperatures of air are 38°C and 29°C, respectively. At the outlet, the corresponding temperatures are 32°C and 29°C, respectively. The process of heat transfer in the airway is described as

Underground coal mines are in principle ventilated by exhausting system, so that

Identify the WRONG statement. Pit bottom air lock

Identify the WRONG statement. The 'temperature inversion' of the atmosphere in surface mines aggravates the problem of

In a CO self rescuer, the purpose of the calcium bromide and lithium chloride mixture is to

IRR of a project is the discount rate at which

The three axes comprising the numerical codification of resources, as per the UNFC, are

Equations of two planes are $z = 4$ and $z = 4 + 3x$. The included angle between the two planes in degrees, is ______

Out of the support categories given for an underground coal mine, identify the ‘active support’.