MINING ENGINEERING GATE PREVIOUS QUESTIONS - 2

1. identify the wrong statement, pit bottom air lock

1. prevents the short-circuiting of air when the air flow is reversed in coal mines
2. has at least three doors
3. has at least one door that has provision of for latching
4. all Doors are in principal designed to open towards high pressure side of the air

2. identify the wrong statement, the temperature inversion of the atmosphere in surface mines aggravates the problem of

1. airborne dust
2. noise
3. ground vibrations
4. visibility

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

1. Dry the incoming air
2. convert the CO catalytically to CO2
3. Absorb and thereby neutralize CO
4. call the inhaled air from excess exothermic heat due to chemical reaction

4. tricone drill bit is a type of

1. cross bit
2. button bit
3. rotary roller bit
4. button drag bit

5. exposure of weak roof in a Junction of a development district in a coal mine can be decreased by

1. increasing dimension of panel barrier
2. stitching side wall
3. increasing support density at Junction
4. staggering the junction

6. the property that cannot be determined from uniaxial compressive strength test of a rock sample fitted with strain gauge is

1. cohesion
2. poisson ratio
3. modulus of elasticity
4. dilation

7. ward- leonard system is provided in the winding system in order to

1. over winding of the cage
2. deceleration of the cage
3. acceleration of the cage
4. over speeding up the cage

8. the equipment not related to extraction of coal from long wall face

1. AFC
2. roadheader
3. powered support
4. DERD Shearer

9. shear strength of rock is not depend on

1. applied normal stress
2. applied shear stress
3. friction angle of the joint plane
4. cohesion of joint plane

10. A flat longwall panel is mined out at an area having subsidence factor a. the measured maximum substance on the surface is S for a mining height of m. the subject is subcritical if

1. S = am
2. S = m/a
3. S greater than am
4. S less than am