A steel bar $$200$$ $$mm$$ in diameter is turned at a feed of $$0.25$$ $$mm/rev$$ with a depth of cut of $$4$$ $$mm.$$ The rotational speed of the work piece is $$160$$ $$rpm.$$ The material removal rate in $$m{m^3}/s$$ is

The binding material used in cemented carbide cutting tools is

Grinding ratio is defined as

Which of the following powder production methods produces spongy and porous particles?