Everyday Science Solar System MCQs for STS BPS 05–15, SPSC & CSS. Hottest planet, fastest rotation, planetary moons, eclipses & light years explained.
Questions about the Solar System in Pakistani competitive exams target specific superlatives and physical facts: which planet has the hottest surface, which rotates clockwise, the names of the largest natural satellites, and the mechanics of solar vs lunar eclipses.
| Attribute | Planet / Fact | Key Value / Measurement | Exam Significance |
|---|---|---|---|
| Closest to Sun | Mercury | 0.39 AU (~58 million km) | Smallest planet; fastest revolution (88 Earth days) |
| Hottest Planet | Venus | ~465°C average surface temp | Runaway greenhouse effect due to 96% CO2 atmosphere |
| Fastest Rotation (Shortest Day) | Jupiter | ~9 hours 55 minutes | Largest planet; Great Red Spot storm |
| Clockwise / Retrograde Rotation | Venus and Uranus | Rotates East to West | Sun rises in the West on Venus |
| Red Planet | Mars | Iron oxide (rust) on surface | Two moons: Phobos and Deimos |
| Speed of Light | Vacuum constant (c) | 300,000 km/s (3 × 10^8 m/s) | Sunlight takes ~8 minutes 20 seconds to reach Earth |
Correct Option: Option B (Venus)
Venus is the hottest planet (~465°C) because its dense atmosphere containing 96% carbon dioxide traps solar heat via an extreme greenhouse effect.
Examiner Trap / Distractor: Candidates incorrectly pick Mercury because it is the closest planet to the Sun.
Correct Option: Option B (The Moon is directly between the Sun and Earth)
A solar eclipse occurs when the Moon aligns directly between the Sun and the Earth, casting its shadow (umbra and penumbra) onto Earth’s surface.
Venus has an extremely dense atmosphere composed of over 96% carbon dioxide, trapping solar infrared radiation in an intense runaway greenhouse effect, keeping surface temperatures at ~465°C day and night.
Light travels at 300,000 km/s and takes approximately 8 minutes and 20 seconds (about 500 seconds) to cover the 149.6 million kilometers from the Sun to Earth.