PPSC MCQs

Deforestation removes tree cover for farming, timber, or development.
It can reduce biodiversity and increase erosion.

Earth completes one rotation in about 24 hours.
The side facing the Sun experiences daylight.

Roots physically hold soil together.
Vegetation also reduces the impact of rain and surface runoff.

Earth's axis is tilted relative to its orbital plane.
This changes day length and solar intensity through the year.

Renewable resources are naturally replaced relatively quickly.
Examples include sunlight, wind, and flowing water.

Mercury has the smallest orbit around the Sun.
It completes a revolution in about 88 Earth days.

Greenhouse gases slow the escape of heat to space.
The natural effect keeps Earth habitable, but added gases increase warming.

Coal, oil, and gas release stored carbon when burned.
The resulting carbon dioxide contributes to climate change.

Methane absorbs infrared radiation efficiently.
It is produced by anaerobic decomposition and livestock digestion.

These pollutants form sulfuric and nitric acids in air.
Acid deposition can harm lakes, soils, buildings, and forests.

Smog reduces visibility and can irritate the respiratory system.
Some smog forms through sunlight-driven chemical reactions.

Incomplete combustion produces carbon monoxide.
The colorless gas can accumulate dangerously in enclosed spaces.