The specific surface of spherical particles is proportional to (where, Dp = diameter of particle)?

Which of the following gases is having the widest explosion limit (about 2 to 81% gas in gasair mixture), rendering it the property of the most explosive gas?

In a nuclear explosion, the energy is released primarily in the form of ________ energy?

Maximum heat transfer rate is achieved in ________ flow?

Initial pressure of oxygen introduced into the ‘bomb’ of the bomb calorimeter for determination of calorific value of coal/fuel oil may be around ________ atm?

Helium is produced on commercial scale from________?