The relief displacement of a building 72 m high on photograph is 7.2 mm and its top appears 10 cm away from principal point. The flying height of the camera, is A. 500 m B. 1000 m C. 1500 m D. 2000 m

The correct answer is B. 1000 m.

The relief displacement of a building is the horizontal displacement of its top relative to its base, as seen on a photograph. It is given by the formula:

$d = \frac{h}{H}$

where $d$ is the relief displacement, $h$ is the height of the building, and $H$

is the flying height of the camera.

In this

case, the relief displacement is 7.2 mm and the height of the building is 72 m. Substituting these values into the formula, we get:

$d = \frac{72}{H} = 7.2$

Solving for $H$, we get:

$H = \frac{72}{7.2} = 1000$ m

Therefore, the flying height of the camera is 1000 m.

The other options are incorrect because they do not result in a flying height that is consistent with the given information.