Discussion
Zinc corrodes at \( 1.2 \) micrometres a year in clean air and \( 6.0 \) micrometres a year in a polluted industrial area. The ratio is
Answer: D
Correct answer: 5.0
Divide the polluted rate by the clean rate:
\[ \frac{6.0}{1.2} = 5.0 \]
Zinc corrodes five times faster in the industrial atmosphere, because sulphur dioxide dissolves in the surface moisture film and attacks the metal, while the hygroscopic sulphate formed keeps the surface wet for longer. Ratios of this order are why galvanised structures in industrial areas need far shorter maintenance intervals than the same structures in clean rural air.
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