687. Ceramic tips are prepared from
A.Tungsten powder
B.Carbon powder
C.Aluminium oxide powder
D.Silicon carbide powder

---

688. Which of the following are cast alloys containing tungsten and chromium carbides in a matrix of cobalt and chromium
A.Mechanites
B.Tungsten carbides
C.Bakelites
D.Stellites

---

689. Carbide tips are fixed to the shanks of cutting tools by
A.Forging
B.Brazing
C.Welding
D.Soldering

---

690. The most wear-resistant grade of carbide used for cutting tools is the straight
A.Iron carbide
B.Calcium carbide
C.Tungsten carbide
D.Nickel carbide

---

691. With increase in cutting speed, the finish
A.Improves considerably
B.Improves slightly
C.Remains same
D.Gets poor

---

692. When turning a long shaft on a lathe, its bending can be prevented by
A.Running the shaft at low speed
B.Using steady rest
C.Using low depth of cut
D.Using sturdy machine

---

693. In oblique cutting system, the chip thickness is
A.Maximum at middle
B.Maximum at sides
C.Minimum at middle
D.Uniform throughout

---