1. Silliminite (Al2O3.SiO2) refractory, which is a neutral refractory, is not used in September 7, 2025 by Admin pottery furnace glass melting furnace crucibles gas retorts ✅ The correct answer is option D.
2. Which is not a high alumina refractory ? September 7, 2025 by Admin Mullite Corrundum Bauxite Dolomite ✅ The correct answer is option D.
3. Slide gates in teeming laddie used for steel pouring in ingot moulds is lined with __________ bricks. September 7, 2025 by Admin bakelite impregnated or fused periclase silica semi-silica fireclay ✅ The correct answer is option A.
4. Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the September 7, 2025 by Admin hearth of the blast furnace. nuclear reactors, missiles & space crafts. insulation of high temperature furnaces. roof of electric furnaces. ✅ The correct answer is option B.
5. Hollow refractory bricks are made by September 7, 2025 by Admin slip casting hand moulding pressing/machine moulding extrusion ✅ The correct answer is option A.
6. Spalling tendency of refractories is reduced by increasing its September 7, 2025 by Admin porosity specific gravity thermal conductivity strength ✅ The correct answer is option A.
7. Which of the following bricks should not be used, if the furnace is to be used intermit-tantly ? September 7, 2025 by Admin Firebricks Silica bricks Silicon carbide bricks Sillimanite ✅ The correct answer is option B.
8. Refractory bricks having lower porosity have September 7, 2025 by Admin high insulating properties low heat capacity low thermal conductivity greater strength ✅ The correct answer is option D.
9. To resist spalling tendency, a refractory should have September 7, 2025 by Admin greater diffusivity. low specific heat. low thermal co-efficient of expansion. all (a), (b) and (c). ✅ The correct answer is option D.
10. Spray test determines the __________ of refractories. September 7, 2025 by Admin resistance to slag penetration resistance to CO attack RUL permanent linear change ✅ The correct answer is option A.