Clouds and weather phenomenon occur in the Troposphere but some clouds are found in the Mesosphere. Why?

1. Meteoric dust particles reflect sunlight causing wispy clouds.
2. Some water particles reach the Mesosphere to form clouds.
3. Ions from the ionosphere deflect sunlight giving the impression of clouds.
4. None of the above.

Which of the following are the functions of the atmosphere?

1. Facilitates the cyclic exchange of gases
2. Maintain of optimum temperature
3. Protects the earth from harmful solar radiation
4. All of the above.

Name the layer which contains ions electrically charged particles which create a sheet like display of light known as Aurora Borealis in the northern hemisphere.

1. Ionosphere
2. Exosphere
3. Stratosphere
4. Mesosphere

Assertion (A): The troposphere is heated more from below than from above.

Reason (R): The troposphere is heated by the incoming solar energy.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R does not explain A.
3. A is true but R is false.
4. A is false but R is true.