Answer:

The type of clouds that are formed at a height of 4000-7000 meters are cumulus clouds.

Cumulus clouds are large, white, puffy clouds that often resemble cotton balls or cauliflower. They are formed by the upward movement of warm air and typically have a flat base and a rounded top. Cumulus clouds are commonly found in fair weather conditions, but they can also develop into thunderstorm clouds under certain conditions.

Explanation:

Cumulus clouds are formed through the process of convection. As the sun heats the Earth's surface, it warms the air above it. This warm air rises and begins to cool as it reaches higher altitudes. When the air cools, water vapor in the air condenses into tiny water droplets or ice crystals, forming a cloud.

The height at which cumulus clouds form, between 4000-7000 meters, is known as the middle level of the atmosphere. At this altitude, the air is usually cool and moist, allowing for the condensation of water vapor into visible clouds.

Cumulus clouds are often associated with fair weather conditions because they indicate the presence of rising warm air. These clouds are usually white or light gray in color, indicating the reflection of sunlight by the water droplets or ice crystals in the cloud.

While cumulus clouds are generally benign and associated with fair weather, they can develop into cumulonimbus clouds under certain conditions. Cumulonimbus clouds are larger and more vertically developed than cumulus clouds. They can produce heavy rain, thunderstorms, lightning, and even tornadoes.

In conclusion, cumulus clouds are formed at a height of 4000-7000 meters and are characterized by their puffy appearance. They are a common sight in fair weather conditions but can develop into cumulonimbus clouds, which bring more severe weather conditions.