Question 11. In an experiment to study coal dust explosibility, it is found that at least 3.0 g of limestone dust
should be added to a sample of 2.0 g of coal dust to ensure that propagation of flame does not take
place. The explosibility factor of coal dust is

Question 12. In a belt conveyor system, function of the snub pulley is to

Question 13. Two meshing spur gear wheels of Module 6 have 24 and 42 teeth. The distance in mm between the
centres of the gear wheels is

Question 14. A core sample of a rock, having diameter 54 mm and length 108 mm, is subjected to axial loading.
If the axial strain and Poisson's ratio are 2000 * 10-6 and 0.28 respectively, the value of
volumetric strain , represented in micro-strain is ___________

Question 15. A bucket wheel excavator with 20 buckets of capacity 0.5 m3 each, rotates at 5 rev/min. The bucket
fill factor is 80%. The excavator loads on to 1200 mm wide belt conveyor. The cross-section area
(m2) of the material on the belt is 0.1B2, where B is the belt width in m. The minimum speed of the
belt in m/s to avoid spillage of material is

Question 16. If the following linear system of equations has non-trivial solutionspx + y + z = 02x + y - 2z = 0x + 2y - 3z = 0the value of p is

Question 17. Given the following,Rescue apparatus        CharacteristicP. Draeger BG-4         1. Open circuit chemical oxygen self-rescuerQ. MSA IW-65             2. Filter type self-rescuerR. Draeger Pulmotor 3. Self-contained breathing apparatusS. Oxyboks                  4. Resuscitation apparatusthe correct match is

Question 18. Given the following,Machine                      ComponentP. Dint header              1. CowlQ. Coal plough             2. Cutting chainR. Road header            3. Loading apronS. Shearer                     4. Static set of bitsthe correct match is

Question 19. Given the following,Equation/formula/law         ApplicationP. Bernoulli equation       1. Pressure loss in laminar flow of fluidQ. Poiseuille equation     2. Drag loss due to regular obstructions in fluid flowR. Bromilow's formula    3. Energy conservation in ideal fluid flowS. Stokes law                    4. Terminal settling velocity of fine particles in fluidthe correct match is

Question 20. A wire of length L is cut into two pieces to construct a circle and an equilateral triangle such that
the combined area is minimum. The length of the wire used to construct the circle is