$5.$Which tool material is preferred for machining hardened steel?a$)$ High$-$speed steelb$)$ Carbidec$)$ Ceramicsd$)$ Cubic boron nitrideWhich tool parameter primarily influences the surface finish of the machined part?a$)$ Cutting speedb$)$ Feed ratec$)$ Depth of cutd$)$ Tool nose radiusWhat is the primary function of chip breakers in machining operations?a$)$ To improve surface finishb$)$ To control chip formation and break them into small piecesc$)$ To reduce tool weard$)$ To prevent built$-$up edge formationWhich tool material is preferred for high$-$speed machining of aluminum alloys?a$)$ High$-$speed steelb$)$ Carbidec$)$ Ceramicsd$)$ Cubic boron nitrideWhich cutting parameter primarily determines the material removal rate?a$)$ Cutting speedb$)$ Feed ratec$)$ Depth of cutd$)$ Tool nose radiusWhat is the primary function of chip breakers?a$)$ To control chip flow directionb$)$ To prevent tool wearc$)$ To improve surface finishd$)$ To break chips into manageable sizes