191. Ferromagnetic ceramic material is not used in the
thermal insulation
transformers
magnetic switches
television sets
✅ The correct answer is option A.
Refractory Technology MCQs
192. Maximum alumina content in high alumina refractory can be as high as __________ percent.
30
50
70
90
✅ The correct answer is option D.
193. Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as __________ percent.
55
70
80
90
✅ The correct answer is option D.
194. Graphite or carbon refractories
exihibit wetting characteristics.
should be used in neutral or reducing atmosphere.
exhibit high shrinkage on thermal treatment.
are not resistant to corrosion by slag.
✅ The correct answer is option B.
195. Which is not a basic refractory ?
Chrome magnesite
Magnesite
Dolomite
Silicon carbide
✅ The correct answer is option D.
196. Cermets are
composite material containing both ceramic & metallic constituents.
having high strength & resistance to high temperature.
used in space vehicles, missiles & nuclear energy plants.
all (a), (b) and (c).
✅ The correct answer is option D.
197. Fusion temperature of pure silica (SiO2) is __________ °C.
1350
1715
2570
2800
✅ The correct answer is option B.
198. Which is not an alumino-silicate refractory?
Fireclay bricks.
Mullite bricks.
Tar dolomite bricks.
High alumina bricks.
✅ The correct answer is option C.
199. Conversion of silica mineral to cristobalite is accompanied by reduction in its
volume
specific gravity
both (a) & (b)
neither (a) nor (b)
✅ The correct answer is option B.
200. Pyrometric cone equivalent (PCE) of a refractory is the measure of its
spalling resistance.
fusion point.
resistance to slag penetration.
resistance to carbon monoxide attack.
✅ The correct answer is option B.