Mining Engineering
GATE MN year:2019 PYQs
Build your understanding with focused practice from past exam papers.
Questions 61–65 of 65. Imported answers require independent review unless marked reviewed.
Question 51
Open questionMNNAT2 marksNeeds review
The insitu stress field around a circular tunnel is shown in the figure.
Points A and B are located at the boundary of the tunnel. If the tangential stress at Point A is 3 times of that at Point B, the value of insitu stress ratio, k is _____.
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Open questionMNNAT2 marksNeeds review
Data related to explosive and blasthole are given below. Assuming 1 kcal to be 4.2 kJ, the power of explosive in GW in the blasthole (round off to one decimal place) is _____.
Parameter | Value |
|---|---|
Diameter of the borehole | 200 mm |
Charge length | 8 m |
Density of ANFO | 0.8 g/cc |
Heat of explosion | 912 cal/g |
VOD | 4500 m/s |
Initiation | Bottom |
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 53
Open questionMNNAT2 marksNeeds review
A rock block of mass 100 kg is to be lifted by a horizontal force P as shown in the figure below.
Smooth rollers are placed between the wedges. The coefficient of static friction between wedge A and surface C and between wedge B and surface D is 0.3. Ignoring the weight of the wedges and the friction between the roller and the wedges, the minimum force P in kg required to lift the block (round off to one decimal place) is _____.
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Open questionMNNAT2 marksNeeds review
A joint plane dipping at 30° intersects the slope edge and the crest as shown in the figure below.
The unit weight of rock is 25 kN/m
, and cohesion and friction angle of the joint surface are 40 kPa and 25° respectively. The safety factor of the shaded block (round off to two decimal places) is _____.Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 55
Open questionMNNAT2 marksNeeds review
The random variable X has probability density function as given by
The value E(X
) (rounded off to one decimal place) is _____.Log in to check the answer
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