Which one of the following does NOT belong to the direct operating cost of a mine?

Lane's algorithm is applied to determine

In an underground coal mine a driller, wearing personal protective equipment, was going to workplace along the travelling roadway. A piece of rock fell down from the roof and hit the person on head causing serious injury. The cause of accident is

In a PERT network, the “time estimates” of an activity are the following: Optimistic time - 2 days, Most likely time - 4 days, and Pessimistic time - 12 days. The expected time and standard deviation of the activity in days are respectively

A vertical photograph of a 40 m high hill is taken from 4.4 km height. If the focal length of the camera is 15 cm, the scale of the photograph is ______.

The operating conditions of a rotary rock drill are: applied thrust: 6.75 kN, revolution: 180 rpm, and penetration rate: 0.15 m/min. The work done per revolution in N-m is ______.

The Absolute amount of energy and density of a booster and ANFO are given below.

The Relative bulk strength of booster is ______.

A deeply seated ore body dips at 70° having an average width of 60 m. The ore body, hanging wall, and footwall are competent. The suitable stoping method for this ore body is

The “yellow boy” formed due to acid mine drainage mainly consists of

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