Question 446General Subjects - Assistant Engineer

The correct answer is B) Backward-curved blade fans. Backward-curved blade fans are characterized by the highest operating efficiency among the given options. This is because the backward-curved blade design creates a more efficient airflow pattern, resulting in lower energy consumption and higher overall system performance compared to other fan types. The other options are less efficient - forward-curved blade fans have a less efficient airflow pattern, flat blade fans do not optimize airflow, and radial blade fans, while effective, are not as efficient as backward-curved designs.