P15 - Electromagnetism - P15.1 Done Flashcards
Why are most magnets made of steel?
As steel does not demagnetise very easily
What is the region around a magnet called?
A magnetic field
What happens to any magnetic material that is placed within a magnetic field?
It experiences the force of the magnet and is either attracted or repelled from it as a result
Why are magnetic field lines and lines of force more concentrated at the poles of a magnet?
As the poles of magnets have the strongest magnet fields
How do you magnetise a magnetic material?
Place it within the magnetic field of a magnetic object
What is the effect of moving something away from a magnet?
The effect of the magnetic field on that object will get less the further you move that object from the magnet
What happens when a star runs out of hydrogen nuclei to fuse in its core?
It reaches the end of its main sequence
What happens to stars about the same size as or smaller than the Sun?
They swell out, cool down, and turn red
What happens to stars larger than the Sun?
They increase in size and turn red - becoming red supergiants
What happens during red supergiant or giant stage?
Helium and other light elements fuse to make heavier elements in the star’s core
What happens after the red giant stage?
The fusion inside the star stops and no more radiation is emitted. It then collapses in on itself because of its own gravity, heating up and turning red to yellow to white. Therefore, a white dwarf is formed, much smaller in diameter than before, and very hot
What happens after the red supergiant stage?
The star collapses in on itself and compresses itself more and more, until exploding dramatically outwards - creating lots of light and outshining a galaxy for up to several weeks
What happens after a white dwarf?
It fades out and goes cold - turning into a black dwarf
What would happen if the sun turned into a supernova in terms of the Earth?
It wold most probably be knocked out of its orbit from the power of the explosion
Why can’t nuclei larger than iron be formed within the sun when it is a red giant?
It would require too much energy
