The equivalent diameter for flow through a rectangular duct of width B and height H is
A
$$\frac{{{\text{HB}}}}{{2\left( {{\text{H}} + {\text{B}}} \right)}}$$
B
$$\frac{{{\text{HB}}}}{{{\text{H}} + {\text{B}}}}$$
C
$$\frac{{2{\text{HB}}}}{{{\text{H}} + {\text{B}}}}$$
D
$$\frac{{4{\text{HB}}}}{{{\text{H}} + {\text{B}}}}$$
Correct Answer: $$\frac{{2{\text{HB}}}}{{{\text{H}} + {\text{B}}}}$$