Explanation

• Cause: Primarily due to excess greenhouse gases like CO₂, CH₄, and N₂O from human activities.
• Effects: Rising temperatures, melting glaciers, extreme weather, and sea-level rise.

Last verified on 08-02-2026

Explanation

• A wind vane (also called a weather vane) shows the direction from which the wind is blowing.
  • Usually installed on rooftops or meteorological stations.
  • Works with a rotating pointer that aligns with the wind direction.

Last verified on 01-02-2026

Explanation

Oxygen is a vital component of the Earth's atmosphere (making up about 21%) and is essential for life

Therefore, oxygen is not considered a part of smog.

Smog in Pakistan mainly consists of harmful air pollutants.

These include sulphur dioxide, nitrogen oxides, and carbon monoxide.

Explanation

Luminosity is the total amount of energy a star emits per second.

It depends on the star’s size and temperature.

Brightness is how bright the star appears from Earth, which can vary with distance.

Magnitude is a scale to measure stellar brightness.

Explanation

Air always moves from regions of high pressure to low pressure.

This movement creates wind and drives weather patterns.

The greater the pressure difference, the stronger the wind.

High-pressure areas are usually associated with clear skies.

Low-pressure areas often bring clouds and precipitation.