For maximum discharge through a chimney, its height should be________?

Cation exchanger is regenerated usually with________?

The total investment in a project is Rs. 10 lakhs and the annual profit is 1.5 lakhs. If the project life is 10 years, then the simple rate of return on investment is________?

If pore diffusion is the controlling step in a solid catalysed reaction, the catalyst________?

A system in which there is exchange of energy but not of mass, is called a/an ________ system?

________ tubes are good substitute for human blood vessels on heart by-pass operation?