Explosives, Accessories and Blasting Practice – 2

1. The amount of energy released by an explosive during blasting is called..?

2. The elements in the delay element of short delay detonator?

3. Which explosive is blasted by safety fuse?

4. The PETN booster occupies only ....% of the total explosive charge?

5. In hard rocks the spacing and burden vary from ......times the height of the bench?

6. In general each shot hole in round u/g covers an area of (sq.m)?

7. In controlled blasting the fly rock should not go height more than?

8. Hazard performance initiation propagation are related to one of the characteristics of an explosive?

9. The powder factor with solid blasting is (te of coal/kg of explosive)?

10. Which is the low density explosive?

11. The rate at which the detonation wave passes through the column of explosive is called?

12. The important characteristic of an explosive which will give an idea about heat and humid condition and time of exposure?

13. The permitted explosive used in u/g in BOS of all gas mines?

14. Shuttering effect is obtained with the explosive having?

15. The VOD of LOX?

16. Relieving hole should be drilled at least ....m away from the misfired hole in u/g?

17. To avoid freezing of NG explosive which agent is mixed?

18. The pattern of cut mostly preferred in tunnels and drifts of small area is?

19. The main element in Fuse head of detonator is..?

20. The current required for the ignition of the fuse head is?

21. The composition of Gunpowder is (charcoal:sulphur nitrate in %)?

22. While using non-incentive delay detonators in BOS the max delay period (milliseconds) between 1st and last shot in deg 1 and 2 is 'X' and deg 3 is 'Y'. Then X is?

23. The delay period between 2 consecutive shots with different delay numbers will not exceed?

24. For irregular ore bodies the preferred drilling pattern is?

25. The peak particle velocity should not increase ...mm/sec?

26. The explosive charge per hole in BG method?

27. Safety tests are carried out for?

28. The process of conversion of chemical energy into heat and mechanical energy is called...?

29. The pattern of cut mostly preferred for laminated strata is?

30. To get lumpy coal or to minimize the coal dust the blasting technique adopted is?

31. To control the fly rock the blasting technique adopted is?