Discussion
Assertion (A): Silica refractory bricks are fired for a long time at high temperature before use.
Reason (R): The quartz must be converted into tridymite and cristobalite, which expand less in service.
Answer: B
Correct answer: Both A and R are true, and R is the correct explanation of A
Both are true and the reason gives the purpose. Quartz undergoes large volume changes as it converts, so a brick still containing it would expand and disrupt itself the first time a furnace was heated. Firing for long periods during manufacture converts the silica to tridymite and cristobalite, whose subsequent expansion in service is far smaller and more gradual - so the brick is dimensionally stable in use.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development