1. Which of the following are a ceramics solids?
a) Metallic, inorganic and amorphous solids
b) Non-metallic, organic and amorphous solids
c) Non-metallic, inorganic and amorphous solids
d) Non-metallic, inorganic and crystalline solids
Answer: c
Explanation: Ceramics are non-metallic, inorganic, amorphous solids and are mostly oxides of metals. Ceramics possess low tensile strength and are brittle.
2. Which of the following is a correct refractory type of quartz?
a) Acidic
b) Basic
c) Neutral
d) Amphoteric
Answer: a
Explanation: Quartz is an acidic refractory and are mostly used in open-hearth furnaces, gas retorts and in glass furnaces.
3. Which one of the following is not an acidic refractory?
a) Quartz
b) Sand
c) Silica brick
d) Dolomite
Answer: d
Explanation: Dolomite is a basic refractory.
| Refractories | |||
|---|---|---|---|
| Differentiating Parameter | Acidic Refractories | Basic Refractories | Neutral Refractories |
| Typical Usage | Used in furnaces, where charge and slag are acidic in nature. | Used in furnaces, where the charge and slag are basic in nature. | Used in furnaces, where the charge and slag either acidic or basic in nature. |
| Examples | Fireclay, Silica, Quartz, Zirconia, etc. | Magnesia, Alumina, Dolomite, etc. | Chromate, Carbide, Mullite, etc. |
4. Which one of the following is not a basic refractory?
a) Magnesite
b) Sand
c) Dolomite
d) Alumina
Answer: b
Explanation: Most of the silica-based refractories, like fire clay, bricks and sand are of acidic refractories.
5. Which one of the following is a neutral refractory?
a) Quartz
b) Sand
c) Silica brick
d) Silicon carbide
Answer: d
Explanation: Silicon carbide is a neutral refractory, whereas sand, quartz and silica brick are acidic refractories.
6. For a M10 grade RCC (Reinforced Cement Concrete), the ratio of cement to aggregate to the sand is?
a) 1:2:3
b) 1:3:4
c) 1:3:6
d) 1:2:6
Answer: c
Explanation: M10 grade of RCC have cement to aggregate to sand ratio equal to 1:3:6.
7. Production of thin sheets of a flexible tape by casting in the particulate forming process may be termed as _________________
a) slip casting
b) hydroplastic forming
c) powder casting
d) tape casting
Answer: d
Explanation: Tape casting is a very old process and is used in the formation of flexible tapes.
8. Which one of the following can act as a modifier in glass forming process?
a) Silicon dioxide
b) Sodium oxide
c) Magnesium oxide
d) Phosphorous oxide
Answer: c
Explanation: Magnesium oxide is used as a viscosity modifier, thus making glass melt viscosity to be in the desired range for proper formation of the filaments.
9. The word ceramic stands for which of the following meaning?
a) Soft
b) Burnt
c) Hard
d) Tough
Answer: b
Explanation: Ceramics convey the meaning of burnt materials. This is so because in olden days, making pottery and bricks involves burning wood, coal and gas.
10. Which one of the following ceramics can be used as a pigment in paints?
a) Silicon carbide
b) Silicon oxide
c) Aluminum oxide
d) Titanium oxide
Answer: d
Explanation: Titanium white (titanium oxide) used as a pigment in pains. It is used so, because of its SFC (self-cleaning capacity) nature.