IGCSE The Universe

Which time period is approximately equal to 24 hours?

• the time for the Sun to orbit the Earth

• the time for the Moon to orbit the Earth

• the time for the Earth to complete one rotation on its axis

• the time for the Earth to orbit the Sun

The nearest star to the Sun is about four light-years away from the Earth. A student makes three statements about the star. Which statements are correct?

• 1, 2 and 3

• 1 and 3 only

• 1 only

• 2 and 3 only

Approximately how long does the Moon take to orbit the Earth?

• 1 day

• 7 days

• 28 days

• 365 days

The Sun transfers energy to the Earth through electromagnetic radiation. What are two of the parts of the electromagnetic spectrum to which most of the energy belongs?

• gamma rays and X-rays

• infrared radiation and visible light

• microwaves and visible light

• radio waves and microwaves

What provides evidence that the Universe is expanding?

• Stars in galaxies outside the Milky Way are all red.

• The Andromeda galaxy is moving toward the Milky Way.

• Light from distant galaxies is shifted to longer wavelengths.

• The Universe is 14 billion years old.

The table shows some elements and some regions of the electromagnetic spectrum. Which row shows one of the most common elements in the Sun and one of the regions in which the Sun radiates most of its energy?

• A

• B

• C

• D

It is summer in the northern hemisphere of the Earth in June. Which statement explains why?

• The Earth spins on its axis in the opposite direction to that in which it rotates around the Sun

• The Earth is closer to the Sun in June.

• The Moon is full in June.

• The north pole of the axis of the Earth’s rotation is tilted towards the Sun in June.

Which statement about the Sun is correct?

• The Sun is a dwarf star consisting mostly of hydrogen and oxygen.

• The Sun is a giant star consisting mostly of helium and carbon dioxide.

• The Sun is a medium-sized star consisting mostly of hydrogen and helium

• The Sun is a medium-sized star consisting mostly of nitrogen and oxygen.

The time taken for the Earth to orbit the Sun is approximately 365 days. The average radius of the Earth’s orbit around the Sun is 1.5 x 10^8 km. What is the average orbital speed of the Earth?

• 4.1 x 10^10 m / s

• 3.0 x10^4 m / s

• 4.8 x 10^3 m / s

• 30 m / s

A space station orbits the Earth at a distance of 7000 km from the Earth’s centre. It makes 15 orbits in every 24-hour period. What is the speed of the space station in its orbit?

• 2900 km /h

• 4400 km /h

• 8800 km /h

• 27 000km / h