1.Ceramic tools are fixed to a tool body by ___________
a) soldering
b) brazing
c) welding
d) clamping
Explanation: The ceramic tools are fixed to a tool body by brazing. These tools have greater tool life than carbide tools.
2. The carbide tools operating at very low cutting speeds
a) reduces tool life
b) increases tool life
c) have no effect on tool life
d) spoils the work piece
Explanation: The carbide tools operating at very low cutting speeds below 30m/min reduces tool life.
3. High speed steel tools retain their hardness upto a temperature of
a) 2500
b) 3500
c) 5000
d) 9000
Explanation: 9000
4. The trade name of a non ferrous cast alloy composed of cobalt, chromium and tungsten is called
a) ceramic
b) stellite
c) diamond
d) cemented carbide
Explanation: The trade name of a non ferrous cast alloy composed of cobalt, chromium and tungsten is called stellite
5. In machining cast iron, no cutting fluid is required.
a) True
b) False
Explanation: True
6. The cutting fluid mostly used for machining alloy steels is :
a) water
b) soluble oil
c) dry
d) sulphurised mineral oil
Explanation: sulphurised mineral oil
7. Cutting fluids are used to:
a) cool the tool
b) improve surface finish
c) cool the workpiece
d) all of the mentioned
Explanation: Functions of cutting fluids are
a) to cool the cutting tool and the workpiece
b) to lubricate the chip, tool and workpiece
c) to help carry away the chips
d) to lubricate some of the moving parts of the machine tool
e) to improve the surface finish
f) to prevent the formation of built up ridge
g) to protect the work against rusting
8. The cutting fluid mostly used for machining steel is:
a) water
b) soluble oil
c) dry
d) heavy oils
Explanation: Soluble oils are used for machining metals of high machinability.
9. Functions of cutting fluids are
a) to cool the cutting tool and the workpiece
b) to lubricate the chip, tool and workpiece
c) to help carry away the chips
d) all of the mentioned
Explanation: Functions of cutting fluids are
a) to cool the cutting tool and the workpiece
b) to lubricate the chip, tool and workpiece
c) to help carry away the chips
d) to lubricate some of the moving parts of the machine tool
e) to improve the surface finish
f) to prevent the formation of built up ridge
g) to protect the work against rusting
10. ______________ form mixtures ranging from emulsions to solutions.
a) Water miscible fluids
b) Neat oils
c) Synthetics
d) None of the mentioned
Explanation: Water miscible fluids form mixtures ranging from emulsions to solutions, which due to their high specific heat, high thermal conductivity, and high heat of vaporisation, are used on about 90% of all metal cutting and grinding operations.