A drilling machine has to be designed with $$8$$ spindle speeds ranging approximately between $$120$$ to $$1200$$ $$rpm.$$ The $${5^{th}}$$ spindle speed is

The base of a brass bracket has to be rough ground to remove the unevenness. The $$4$$ wheels available in the store. The appropriate wheel is

A milling cutter having $$8$$ teeth is rotating at $$100$$ $$rpm.$$ The work piece feed is set at $$40mm/min$$. The feed per tooth is

The diameter and rotational speed of a job are $$100mm$$ and $$500$$ $$rpm$$ respectively. The high spots (chatter marks) are found at a spacing of $$30$$ $$deg$$ on the job surface. The chatter frequency is