Grade 12 Physics Quiz

At what stage in a star's lifecycle does it begin to fuse helium gas instead of hydrogen?

• Main Sequence Stage

• Red Giant Stage

• White Dwarf Stage

• None of the above

The primary determinant of a star's lifespan is its mass.

• True

• False

A supernova explosion is responsible for forming elements heavier than hydrogen and helium.

• True

• False

In a planetary nebula a star collapses into a red giant.

• True

• False, white dwarf

Parallax is a method used to determine.

• The luminosity of stars

• The distance to nearby stars

• The temperature of stars

• None of the above

Luminosity is defined as

• The total rate at which electromagnetic energy, or light, is being emitted from the star.

• A log-scale measure of the actual luminosity of a star.

• A diagram which compares stars according to their temperatures and luminosities.

• None of the above

The apparent magnitude is a log-scale measure of the actual luminosity of a star.

• True

• False, absolute magnitude

The correct sequence of the lifecycle of a star is Protostar → Main Sequence → Red Giant → Planetary nebula → White dwarf

• True

• False

Which stars use the carbon-nitrogen-oxygen cycle to fuse hydrogen to helium?

• Small stars

• Medium-sized stars

• Large stars

• None of the above

What is the significance of stellar nucleosynthesis?

• It produces the elements that make up the new stars and accompanying solar system

• It generates magnetic fields in space

• It maintains the cosmic background radiation

• None of the above