Continuous rails for Indian railways are welded by ........ Welding process.

Thrust force in drilling can be reduced by .................A............... the point angle and by ..........B.......... the helix angle of the drill

(a) increasing / reducing
(b) increasing / reducing

Feed motion can be provided with stepper motors in $$CNC$$

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