Question

The gaseous envelope around the earth is known as atmosphere. The lowest layer of this is extended up to 10 km from sea level, this layer is.
A. stratosphere
B. troposphere
C. mesosphere
D. hydrosphere

Answer 1

The atmosphere changes as the distance from the surface of earth increases, so the atmosphere is divided into five parts. The lowest layer of the atmosphere which extended up to 10 km from sea level is the layer in which humans live and birds fly.

Complete answer:
The gaseous envelope which covers the earth is known as the atmosphere. The five layers of the atmosphere are:
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
- Exosphere
The troposphere is the lowest layer of the atmosphere. It extends 10 km above sea level. The outer surface of the troposphere is the tropopause. In this layer temperature decreases with increasing altitude. Aviation-related activities take place in the troposphere.
The second layer is the stratosphere which extends up to 50 km above the earth surface. The outer surface of the stratosphere is stratopause. In the stratosphere temperature increases on increasing altitude.
The third layer is the mesosphere which extends up to 85 km above the sea level. The outer surface of the mesosphere is mesopause. The mesosphere is the coldest place.
The fourth layer is the thermosphere which extends to an altitude of 500 km above the earth surface. The outer surface of the thermosphere is thermopause. Thermopasue is also referred to as exobase.
Fifth layer is the exosphere which extends up to 700 km above sea level.

Therefore, option (B) troposphere is correct.

Note: Clouds appear and sounding rockets fly in the mesosphere. Meteor burns in the mesosphere. Meteors are the rocky bodies. Ozone is present in the stratosphere layer which absorbs ultraviolet radiation. Satellites are positioned in the thermosphere layer. In the exosphere, low-density hydrogen and helium gases are found.