1. Which of the following is not used as binders for mould materials?
a) Bentonite
b) Kaolinite
c) Backelite
d) Illite
Explanation: Backelite is a material which increases hardness beyond a limit which is acceptable for mold materials as well as its deformation takes place too early as plastic deformation. Hence, it is not used as a binder.
2. Which of the following is not used as an additive?
a) Dextrin
b) Coal dust
c) Pitch
d) Zinc
Explanation: Zinc is an alloying element and is not considered as additive.
3. Nitriding process is used to increase surface hardness for which of the following materials?
a) Alloy steels
b) Low carbon steels
c) Medium carbon steels
d) High carbon steels
Explanation: Alloy steels ( due to low carbon content) can easily undergo nitriding process.
4. The famous iron pillar located near Qutab Minar in New Delhi is made up of which material?
a) Stainless steel
b) Malleable iron
c) Mild steel
d) Wrought iron
Explanation: Malleable iron is a raw kind of type of iron which was used in the making of Iron pillar.
5. Which of the following is not a source of moulding sand?
a) Sea
b) Lakes
c) Desert
d) Forests
Explanation: There are a variety of soils which can be found in forests. But the soils found there cannot be used for casting purposes. Hence forests are not a source for finding moulding sand, whereas sea, lakes and deserts are a source of finding them.
6. Which of the following is not a type of moulding sand?
a) Red sand
b) Natural sand
c) Synthetic sand
d) Loam sand
Explanation: Red sand is not counted among the moulding sands, whereas natural sand, synthetic sand and loam sand are various other types of moulding sand, which can be effectively used for casting processes.
7. What is the percentage composition of clay in natural sand?
a) 22-31%
b) 3-10%
c) 5-20%
d) 18-29%
Explanation: In natural sands, the percentage composition of clay is approximately 5-20% as the binding material. If the percentage composition is less than that like 3 to 10%, then the binding action will not take place effectively.
8. What is the percentage composition of water in natural sands?
a) 2-4%
b) 5-8%
c) 6-9%
d) 10-13%
Explanation: Water is an important agent used in sands, but its composition should be inside the desired range. The percentage composition of water in natural sands is around 5-8% for mixing before making a mould.
9. What is mixed with natural sand to make it semisynthetic sand?
a) Bentonite
b) Barelelne
c) Cubane
d) Prismane
Explanation: The addition of a material like bentonite in its sand form, is because of the need to enhance the sand properties. Bentonite is mixed with natural sand to make it semisynthetic sand and thus improving its properties.
10. Which sand is used for casting cast irons and non-ferrous metals?
a) Loam Sand
b) Natural Sand
c) Synthetic Sand
d) Refractory sand grain
Explanation: For casting iron and non-ferrous metals, natural sand is used. The loam sand, the synthetic sand and the refractory grain sand do not play any role in casting them.