Refractory Technology Carbon refractories Do not resist temperature fluctuations Are not attacked by slags, as they are not wetted by melts Do not burn/oxidise, when exposed to air on heating Have extremely low thermal & electrical conductivities Do not resist temperature fluctuations Are not attacked by slags, as they are not wetted by melts Do not burn/oxidise, when exposed to air on heating Have extremely low thermal & electrical conductivities ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Natural silica Mainly contains quartz Is not stable at high temperature Transforms to other allotropic forms i.e tridymite and cristoballite involving very high volume changes All of these Mainly contains quartz Is not stable at high temperature Transforms to other allotropic forms i.e tridymite and cristoballite involving very high volume changes All of these ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Segar cones are used for the determination of __________ of refractories. Electrical conductivity Softening temperature Resistance to slag attack Spalling resistance Electrical conductivity Softening temperature Resistance to slag attack Spalling resistance ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Which of the following has the lowest electrical resistivity? Fireclay Zircon Alumina Graphite Fireclay Zircon Alumina Graphite ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Furnace atmosphere for softening temperature determination of refractories (in which segar cones are placed) should be Neutral Neither A nor B Oxidising Either A or B Neutral Neither A nor B Oxidising Either A or B ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Cermets are All of these Having high strength & resistance to high temperature Used in space vehicles, missiles & nuclear energy plants Composite material containing both ceramic & metallic constituents All of these Having high strength & resistance to high temperature Used in space vehicles, missiles & nuclear energy plants Composite material containing both ceramic & metallic constituents ANSWER DOWNLOAD EXAMIANS APP
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