Discussion
Which change would NOT reduce ground level concentration from a stack?
Answer: D
Correct answer: Reducing the exit velocity
Reducing the exit velocity would not reduce ground level concentration - it raises it. The exit velocity supplies the momentum contribution to plume rise, so cutting it lowers the effective stack height, and since the maximum varies roughly as \( 1/H^2 \) the ground level concentration goes up. A very low exit velocity can also let the plume be drawn into the downwash behind the stack.
The other three all help. A taller stack raises \( H \) directly, a hotter exhaust increases the buoyancy that drives plume rise, and a windier day dilutes the emission through more air per second.
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