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  • Question
  • silicon carbide refractories have very low


  • Options
  • A. refractoriness (< 1700°C).
  • B. thermal conductivity.
  • C. resistance to thermal shock.
  • D. none of these.

  • Correct Answer
  • none of these. 


  • Refractory Technology problems


    Search Results


    • 1. Nuclides having the same atomic numbers are termed as

    • Options
    • A. isotopes
    • B. isomers
    • C. isotones
    • D. isobars
    • Discuss
    • 2. Atoms with same number of neutrons, but different number of nucleons are called

    • Options
    • A. isotones
    • B. isobars
    • C. isotopes
    • D. isoters
    • Discuss
    • 3. Percentage of U-238 in natural uranium is around

    • Options
    • A. 0.71
    • B. 99.29
    • C. 0.015
    • D. 29.71
    • Discuss
    • 4. Which is a fertile nuclear fuel?

    • Options
    • A. U-233
    • B. U-235
    • C. Pu-239
    • D. Th-232
    • Discuss
    • 5. Thorium metal

    • Options
    • A. resembles steel in appearance.
    • B. is less hard (in the range of silver).
    • C. is highly ductile.
    • D. all (a), (b) and (c).
    • Discuss
    • 6. Cold crushing strength of ordinary fireclay brick is about 950 kg/cm2 . On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as __________ kg/cm2 .

    • Options
    • A. 450
    • B. 250
    • C. 150
    • D. 65
    • Discuss
    • 7. Which of the following is not a neutral refractory?

    • Options
    • A. Silicon carbide
    • B. Magnesite
    • C. Chromite
    • D. Graphite
    • Discuss
    • 8. Silica refractories

    • Options
    • A. crack when subjected to sudden change of temperature.
    • B. can not be used in the dome of hot blast stoves.
    • C. have lower thermal conductivity than fireclay bricks.
    • D. all (a), (b) and (c)
    • Discuss
    • 9. With increase in the alumina content in firebricks, its fusion point (refractoriness)

    • Options
    • A. decreases linearly
    • B. remains unchanged
    • C. increases
    • D. decreases
    • Discuss
    • 10. Which is not an alumino-silicate refractory?

    • Options
    • A. Fireclay bricks.
    • B. Mullite bricks.
    • C. Tar dolomite bricks.
    • D. High alumina bricks.
    • Discuss


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