$4.$What 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 sizesWhich tool material offers the best combination of hardness and toughness for general machining applications?a$)$ High$-$speed steelb$)$ Carbidec$)$ Ceramicsd$)$ Cubic boron nitrideHow does the relief angle influence the cutting process?a$)$ It controls the width of the cutb$)$ It reduces friction between the tool and workpiecec$)$ It provides clearance between the tool and the workpieced$)$ It determines the depth of cutWhich tool angle is primarily responsible for controlling the chip flow direction?a$)$ Rake angleb$)$ Relief anglec$)$ Clearance angled$)$ Side cutting edge angleThe primary function of chip breakers is to:a$)$ Reduce cutting forcesb$)$ Control chip formation and break them into small piecesc$)$ Prevent built$-$up edge formationd$)$ Improve tool rigidityWhat is the primary function of the rake angle in cutting tool geometry?a$)$ To control the direction of chip flowb$)$ To determine the width of the cutc$)$ To reduce cutting forcesd$)$ To provide clearance between the tool and workpiece