China Civil UAV Theory Questions — Questions 491–500

UAV-Q0491. In the troposphere, air motion in the ______ layer is most affected by terrain disturbance and surface friction, with chaotic airflow

Explanation

The lower troposphere (below 1500 m above ground) is most affected by terrain disturbance and surface friction, with chaotic airflow; it is also called the “friction layer”.

UAV-Q0492. Fog usually occurs when near-surface air cools to its dew point; it is cloud starting at the surface _______.

Explanation

Fog is cloud starting at the surface within 50 feet, formed when near-surface air cools to its dew point and water vapor condenses.

UAV-Q0493. Turbulence related to ground buildings depends on obstacle size and basic wind speed, even more so in mountain areas. When wind crosses a mountain ridge:

Explanation

When wind crosses a mountain ridge, airflow on the windward side flows steadily upward, while on the leeward side airflow sinks and turbulence increases.

UAV-Q0494. Satellite cloud images are mainly divided into which two categories?

Explanation

Satellite cloud images are classified by detection method into infrared images (reflecting temperature) and visible-light images (reflecting reflectivity).

UAV-Q0495. How does temperature affect aircraft takeoff roll distance?

Explanation

High temperature means low air density, slow aircraft acceleration, higher liftoff speed, and a longer takeoff roll. Options B and C describe density changes incorrectly.

UAV-Q0496. On satellite cloud images, infrared image tone depends on:

Explanation

Study note: for infrared images, look at temperature; for visible-light images, look at solar radiation. Infrared images detect a target's infrared radiation to reflect temperature: the lower the temperature, the whiter the tone.

UAV-Q0497. Turbulence related to ground buildings depends on ______, which affects any aircraft's takeoff and landing performance and can cause very serious danger.

Explanation

Study note: size and speed. Turbulence intensity relates to obstacle size and basic wind speed: the larger the obstacle and the higher the wind speed, the stronger the turbulence.

UAV-Q0498. Generally, an air mass's vertical height can reach several to over ten kilometers, often extending from the ground to the tropopause. Its horizontal range is:

Explanation

An air mass's horizontal range can reach tens to thousands of kilometers, with vertical height from several to over ten kilometers.

UAV-Q0499. When wind blows, the local phenomenon of constantly changing wind direction and alternating strong and weak wind speeds is called

Explanation

Study note: gusty, on-and-off wind means gustiness. Gustiness is the phenomenon of constantly changing local wind direction and alternating strong and weak wind speeds, caused by vortices in the airflow.

UAV-Q0500. On satellite cloud images, visible-light image tone depends on:

Explanation

Study note: for infrared images, look at temperature; for visible-light images, look at solar radiation. Visible-light images depend on the target's reflection of sunlight: the higher the reflectivity, the whiter the tone, reflecting cloud thickness and other features.