In spot welding of aluminium sheets, the welding current should be .........A........ and weld time should be kept ............B......... than for $$MS$$ sheet of same thickness.

(A). higher / lower, (B). higher / lower

High alloy steel components are preheated before welding for reducing

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 $$CNC$$