List of top Photogrammetry Questions on Scale of Vertical Aerial Photograph and Flying Height asked in GATE GE

For a camera with focal length \( 150\ \text{mm} \) and a \( 30\ \text{cm} \times 30\ \text{cm} \) format size, what height above ground (in meters) is necessary for a vertical photograph to cover an area of \( 9\ \text{km}^2 \)?