P1 Astrophysics iGCSE Edexcel

Which best represents the path of a planet P as it orbits the Sun? Drawing is not to scale.

• A

• B

• C

• D

The orbital path of a satellite is shown in the sketch. Use the sketch to answer the question.

In which of the positions A through D does the satellite have the least speed ?

• A

• B

• C

• D

Which of the following are in the correct order of size from largest to smallest?

• galaxy, universe, planet, star

• star, planet, comet, galaxy, moon

• galaxy, universe, star, planet, moon

• universe, galaxy, star, planet, comet

Where do stars form?

• They do not form – they have been here since the beginning of the Universe.

• They form in a supernova.

• They form in stellar nebulae.

• They form from dead planets

What causes the nuclear fusion to begin in a star?

• lots of dust particles ignite

• helium molecules being produced

• intense heat and pressure

• gravity

When a star is in the main sequence, what can be said about the forces acting inside the star?

• The outward pressure is greater than the gravitational pull.

• The gravitational pull is greater than the pressure from the fusion reactions.

• All the forces acting on the star are unbalanced.

• The inward gravitational attraction is equal to the outward pressure from the fusion reactions.

How might it be noticeable that a star is now fusing helium rather than hydrogen atoms?

• The star cools and becomes a white dwarf.

• The star shrinks then expands to form a red giant.

• A black hole is created.

• The star stops glowing.

The nuclear reaction that takes place in the core of the stars is

• Nuclear disposition

• Nuclear fission

• Nuclear fusion

• Nuclear composition

A large ensemble of stars, all interacting through the gravitational force and orbiting around a common center is called

• Constellation

• Galaxy

• Star cluster

• Star show

Mira is a star found in the giants section of the Hertzsprung–Russell diagram. What is the next step for Mira in its lifecycle?

• neutron star

• supernova

• cools to become a white dwarf

• condenses to become a black hole