The velocity of flue gases (V) through the chimney under a static draught of (H') metres is given by
A. $${\text{V}} = \sqrt {2{\text{gH}}'} $$
B. $${\text{V}} = \sqrt {\frac{{2{\text{g}}}}{{{\text{H}}'}}} $$
C. $${\text{V}} = \frac{{{\text{H}}'}}{{\sqrt {2{\text{g}}} }}$$
D. $${\text{V}} = 2{\text{g}}\sqrt {{\text{H}}'} $$
Answer: Option A

under root missing