IGCSE Physics 6.1 Earth and the Solar System MCQs – 30 Practice Questions with Answers (Cambridge 0625)
Free practice MCQs for Cambridge IGCSE Physics (0625) Section 6.1, The Earth and the Solar System. Test yourself on day and night, the seasons, the Moon and its phases, eclipses, planets, orbits and satellites – then open each Show Answer toggle to check the worked explanation.
Formula recap: Space Physics needs very few equations, but the key facts – orbital periods, the cause of the seasons and satellite orbits – are all collected on our IGCSE Physics Formula Sheet. Revise it alongside these questions.
Day, Night, the Year & Seasons
Q1. Day and night on Earth are caused by
- (A) the Earth orbiting the Sun once a year
- (B) the Earth rotating on its axis once every 24 hours
- (C) the Moon orbiting the Earth
- (D) the Sun moving across the sky
Show Answer
Answer: B – The Earth spins on its axis once every 24 hours. The side facing the Sun has day while the side facing away has night.
Q2. Approximately how long does the Earth take to complete one orbit of the Sun?
- (A) 24 hours
- (B) 27.3 days
- (C) 365.25 days
- (D) 30 days
Show Answer
Answer: C – One full orbit of the Sun (one year) takes about 365.25 days.
Q3. Leap years, with an extra day in February every four years, are needed because
- (A) the year is 365.25 days long, and the extra quarter days add up to one day every four years
- (B) the Earth’s rotation is slowing down
- (C) the Moon’s orbit changes the calendar
- (D) February is shorter than the other months
Show Answer
Answer: A – A calendar year has 365 days, but the Earth actually takes 365.25 days to orbit the Sun. The four quarter days make one extra day every four years.
Q4. The seasons on Earth are caused by
- (A) the Earth being closer to the Sun in summer
- (B) the Sun producing more energy in summer
- (C) the Earth’s distance from the Sun changing a lot during the year
- (D) the Earth’s axis being tilted at about 23.5° to its orbit
Show Answer
Answer: D – The axis is tilted at about 23.5°. As the Earth orbits, each hemisphere takes a turn at tilting towards the Sun, which produces the seasons.
Q5. It is summer in the northern hemisphere mainly because
- (A) that hemisphere is tilted towards the Sun, so the Sun’s rays are more concentrated and the days are longer
- (B) the Earth is at its closest point to the Sun
- (C) the northern hemisphere rotates faster in summer
- (D) the Sun rises earlier there
Show Answer
Answer: A – Tilting towards the Sun means the rays strike more directly (more energy per unit area) and daylight lasts longer. It is a common misconception that summer happens because the Earth is closer to the Sun – the distance hardly changes.
Q6. When the northern hemisphere is having its summer, the southern hemisphere is having its
- (A) summer as well
- (B) winter
- (C) spring
- (D) rainy season everywhere
Show Answer
Answer: B – The two hemispheres tilt in opposite senses: when the north tilts towards the Sun, the south tilts away, so their seasons are opposite.
Q7. In summer, a hemisphere receives more energy from the Sun because the rays
- (A) travel a shorter distance to reach it
- (B) pass through less of the Sun’s atmosphere
- (C) strike the surface more directly, so the energy is spread over a smaller area, and the days are longer
- (D) are reflected less by the oceans
Show Answer
Answer: C – Nearly overhead rays concentrate the same energy onto a smaller area, and longer days give more hours of heating.
Q8. Close to the North Pole in midsummer,
- (A) the Sun never rises
- (B) day and night are each exactly 12 hours
- (C) the Sun sets for only a few minutes each day
- (D) the Sun can stay above the horizon for 24 hours a day, for weeks on end
Show Answer
Answer: D – Because the pole is tilted towards the Sun, it stays in daylight as the Earth rotates. Right at the pole there can be about six months of continuous daylight, followed by about six months of darkness.
Q9. The Earth’s axis is tilted at an angle of approximately
- (A) 90°
- (B) 23.5°
- (C) 45°
- (D) 0°
Show Answer
Answer: B – The axis is tilted about 23.5° from the line perpendicular to the Earth’s orbit, and points in the same direction throughout the year.
Q10. At a place on the equator, throughout the year
- (A) day and night stay roughly equal, about 12 hours each
- (B) the days are always much longer than the nights
- (C) there are six months of daylight then six months of darkness
- (D) the Sun never sets in summer
Show Answer
Answer: A – The equator is barely affected by the tilt, so it gets about 12 hours of day and 12 hours of night all year round.
The Moon, Phases & Eclipses
Q11. The Moon takes approximately how long to complete one orbit of the Earth?
- (A) 24 hours
- (B) 365.25 days
- (C) 27.3 days
- (D) 7 days
Show Answer
Answer: C – The Moon orbits the Earth in about 27.3 days.
Q12. From Earth we always see the same face of the Moon because
- (A) the Moon rotates on its axis in the same time (about 27.3 days) as it takes to orbit the Earth
- (B) the Moon does not rotate at all
- (C) the far side of the Moon is always in darkness
- (D) the Earth rotates at the same rate as the Moon orbits
Show Answer
Answer: A – The Moon’s rotation period exactly matches its orbital period, so the same side always faces the Earth.
Q13. We can see the Moon at night because it
- (A) produces its own light
- (B) glows because it is hot
- (C) reflects light from the Earth
- (D) reflects sunlight towards the Earth
Show Answer
Answer: D – The Moon is not a light source. It shines only by reflecting sunlight.
Q14. At new moon, the positions of the Sun, Moon and Earth are
- (A) the Earth is between the Sun and the Moon
- (B) the Moon is between the Sun and the Earth
- (C) the Sun is between the Moon and the Earth
- (D) the Moon is at right angles to the Sun-Earth line
Show Answer
Answer: B – At new moon the Moon lies between the Sun and the Earth, so its sunlit side faces away from us and the side facing us is dark.
Q15. A full moon is seen when
- (A) the Moon is between the Sun and the Earth
- (B) the Moon is closest to the Earth
- (C) the Earth is between the Sun and the Moon, so the whole of the Moon’s sunlit face is visible
- (D) the Moon is fully inside the Earth’s shadow
Show Answer
Answer: C – With the Earth between the Sun and the Moon, the entire face of the Moon turned towards us is lit up – a full moon.
Q16. A lunar eclipse happens when
- (A) the Earth passes between the Sun and the Moon, and the Earth’s shadow falls on the Moon
- (B) the Moon passes between the Sun and the Earth
- (C) the Moon moves behind the Sun
- (D) clouds cover the Moon
Show Answer
Answer: A – In a lunar eclipse the Earth is between the Sun and the Moon, so the Moon moves into the Earth’s shadow and darkens. This can only happen at full moon.
Q17. A solar eclipse happens when
- (A) the Earth passes between the Sun and the Moon
- (B) the Earth’s shadow falls on the Sun
- (C) the Moon moves into the Earth’s shadow
- (D) the Moon passes between the Sun and the Earth, and the Moon’s shadow falls on part of the Earth
Show Answer
Answer: D – In a solar eclipse the Moon is between the Sun and the Earth. People inside the Moon’s small shadow see the Sun blocked out. This can only happen at new moon.
Q18. Eclipses do not happen every month because
- (A) the Moon is too far away most of the time
- (B) the Moon’s orbit is tilted relative to the Earth’s orbit around the Sun, so the three bodies are usually not exactly in line
- (C) the Earth’s shadow is too small
- (D) the Moon only orbits during the day
Show Answer
Answer: B – The Moon’s orbit is tilted by a few degrees, so at most new and full moons the shadow misses. Eclipses need an exact line-up.
Q19. Which sequence of Moon phases is in the correct order?
- (A) full moon, new moon, first quarter, last quarter
- (B) new moon, full moon, first quarter, last quarter
- (C) new moon, first quarter, full moon, last quarter
- (D) first quarter, new moon, last quarter, full moon
Show Answer
Answer: C – As the Moon orbits the Earth, the lit part we see grows (waxes) from new moon through first quarter to full moon, then shrinks (wanes) through last quarter back to new moon.
Q20. The phases of the Moon are caused by
- (A) different amounts of the Moon’s sunlit half being visible from the Earth as the Moon orbits
- (B) the Earth’s shadow covering part of the Moon
- (C) clouds covering part of the Moon
- (D) the Moon rotating so that different faces point at the Earth
Show Answer
Answer: A – Half of the Moon is always lit by the Sun. As the Moon orbits, we see more or less of that lit half. The Earth’s shadow is only involved in a lunar eclipse, not in the monthly phases.
Planets, Orbits & Satellites
Q21. Which is the correct order of the planets, starting with the one closest to the Sun?
- (A) Venus, Mercury, Earth, Mars
- (B) Mercury, Venus, Earth, Mars
- (C) Mercury, Earth, Venus, Mars
- (D) Earth, Venus, Mercury, Mars
Show Answer
Answer: B – The full order is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
Q22. The planets stay in orbit around the Sun because of
- (A) the gravitational attraction between each planet and the Sun
- (B) the magnetic field of the Sun
- (C) the push of the Sun’s light
- (D) the rotation of the Sun
Show Answer
Answer: A – Gravity pulls each planet towards the Sun and provides the centripetal (centre-seeking) force that keeps it moving in its orbit instead of flying off in a straight line.
Q23. Compared with a planet close to the Sun, a planet further from the Sun
- (A) has a shorter orbital period
- (B) moves faster in its orbit
- (C) feels a stronger gravitational pull from the Sun
- (D) takes longer to complete one orbit and moves more slowly
Show Answer
Answer: D – The further a planet is from the Sun, the weaker the gravity and the longer its orbit path, so its orbital period is longer. Neptune takes about 165 years, compared with 88 days for Mercury.
Q24. How does a planet differ from a star?
- (A) A planet is bigger than a star
- (B) A planet orbits the Earth
- (C) A planet does not produce its own light; it orbits a star and shines by reflecting the star’s light
- (D) A planet is made only of gas
Show Answer
Answer: C – Stars produce their own light by nuclear reactions. Planets are much smaller bodies that orbit a star and are visible only because they reflect its light.
Q25. For a satellite to be geostationary, its orbital period must be
- (A) 27.3 days
- (B) 24 hours
- (C) 90 minutes
- (D) 365.25 days
Show Answer
Answer: B – A geostationary satellite orbits in exactly 24 hours, the same time the Earth takes to rotate once, so it stays above the same point on the equator.
Q26. A geostationary satellite must orbit
- (A) above the equator, moving in the same direction as the Earth rotates
- (B) above the North Pole
- (C) in the opposite direction to the Earth’s rotation
- (D) very close to the Earth’s surface
Show Answer
Answer: A – It orbits high above the equator (about 36 000 km up) in the same direction as the Earth spins and with a 24-hour period, so it appears fixed in the sky – ideal for TV dishes, which do not need to move.
Q27. Satellites in low polar orbits are most useful for
- (A) television broadcasting to fixed dishes
- (B) staying above one city all day
- (C) replacing mobile phone masts
- (D) weather monitoring and mapping, because the Earth rotates beneath them so they scan the whole surface
Show Answer
Answer: D – A polar-orbit satellite passes over the poles while the Earth turns underneath it, so over many orbits it images the entire surface – perfect for weather forecasting and mapping.
Q28. Geostationary satellites are mainly used for
- (A) photographing every part of the Earth each day
- (B) studying the Moon
- (C) television broadcasting and communications
- (D) measuring the depth of the oceans
Show Answer
Answer: C – Because a geostationary satellite stays above the same point, it can relay television and communication signals continuously to fixed receiver dishes.
Q29. Sunlight takes approximately how long to travel to the Earth?
- (A) 8 seconds
- (B) 8 minutes
- (C) 8 hours
- (D) it arrives instantly
Show Answer
Answer: B – Light travels at 3.0 x 108 m/s and the Sun is about 1.5 x 1011 m away, so the journey takes roughly 500 seconds – about 8 minutes.
Q30. The force that keeps the Moon in orbit around the Earth, and also provides the centripetal force for the planets, is
- (A) friction
- (B) magnetism
- (C) air resistance
- (D) gravity
Show Answer
Answer: D – The gravitational attraction between the Earth and the Moon pulls the Moon towards the Earth, providing the centripetal force for its orbit – just as the Sun’s gravity holds the planets.
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All questions on this page are original practice questions written for QuaidianPoint – they are not Cambridge past-paper questions.