Chlorine dose 5 mg/L এবং Residual Chlorine 0.5 mg/L হলে Chlorine demand কত?
Chlorine dose 5 mg/L এবং Residual Chlorine 0.5 mg/L হলে Chlorine demand কত?
From the LGED Sub-Assistant Engineer (Civil) November 2026 – Preliminary (BPSC) exam, question 45 of 100.