(A) Paper 2 Wrongs

Question 1

What is the temperature of the Sun’s core?

Answer 1

15 Million K

Question 2

What is the temperature of the Sun’s radioactive and convective zones?

Answer 2

2 million K to 6 million K

Question 3

What is the role of the corona and what is it’s average temperature?

Answer 3

High velocity solar particles interact with magnetic field and emit X rays. 2 million K

Question 4

What are other objects orbiting between Jupiter and the Kuiper belt known as?

Answer 4

Centuars

Question 5

What do scientists believe caused rings around a planet?

Answer 5

May be due to Moon coming too close and being ripped apart by the parent body

Question 6

Compare convex and concave lenses

Answer 6

Convex lens: enlarge an image + viewed by another convex lens
Concave: mirror can capture light and focus it to a point where it is viewed by a convex lens

Question 7

Describe a Galilean refracting telescope

Answer 7

• Uses a concave lens as an eyepiece
• fixed focus
• limited FOV

Question 8

Describe a Keplerian refracting telescope

Answer 8

• Uses a convex lens
• Larger or heavier
• Focusable but photos are inverted

Question 9

Describe a Newtonian reflecting telescope

Answer 9

• has two mirrors
• concave mirror
• another mirror up the tube at 45 degree angle

Question 10

Describe a Cassegrain reflecting telescope

Answer 10

• reflects light onto a secondary mirror
• mirror 2 faces the primary mirror + reflects onto it but focused through a small hole behind the primary

Question 11

Define aperture

Answer 11

The amount of light a telescope receives: diameter of its objective lens or mirror

Question 12

Why is aperture important?

Answer 12

The larger the size of the aperture, the more light that enters the telescope, making objects brighter

Question 13

What is used to determine the resolution of a telescope?

Answer 13

• wavelength
• diffraction of light
• quality of telescope
• contrast
• brightness
• observer’s eyesight

Question 14

How is resolution calculated?

Answer 14

wavelength/ diameter

Question 15

What is the focal length of a telescope?

Answer 15

How far light travels inside a telescope before it reaches a focus point

Question 16

How do emission nebulae emit radiation?

Answer 16

Stars inside or near the nebula warm the gas through UV radiation, causing the electrons to ionise + emit radiation

Question 17

Describe what happens at the red giant stage

Answer 17

• Slows its rate of fusion
• Lacks outward pressure needed to maintain its size
• Increases in size until it starts consuming heavier elements
• When it runs out of fuel it shrinks to a white dwarf

Question 18

What are the two types of supernova?

Answer 18

1) Star takes mass from a giant then explodes
2) Red giants core with a mass greater than several solar masses collapses in on itself

Question 19

What are the two formations of neutron stars?

Answer 19

1) Star between 4-25 solar masses will grow into a red supergiant, explode then form a neutron star
2) White dwarf, which can’t contain its mass through electron degeneracy and exceeds 1.4 solar masses will become a neutron star

Question 20

How are black holes formed?

Answer 20

If the mass of the core of a star is greater than 3 solar masses, gravitational collapse occurs which forms a supernova then collapses some more to form a black hole

Question 21

What are the two main theories about galaxy formation?

Answer 21

1. Vast clouds of gas and dust collapsed gravitationally allowing stars to be formed
2. Lumps of matter present in the universe clumped together under their mutual gravitational attraction to form galaxies

Question 22

Where are star and globular clusters positioned concerning our galaxy?

Answer 22

Globular clusters: surround the halo (dusty area around the galaxy)
Star clusters: near the arms

Question 23

Describe a Seyfert galaxy

Answer 23

• bright nuclei
• emit strongly in the IR, UV and X ray regions
• typically spiral or irregular

Question 24

Describe a Quasar galaxy

Answer 24

• emit strongly in radio waves, UV and Xray regions
• extremely large black holes
• furthest + oldest objects we know of
• large redshifts

Question 25

Why is the value of the Hubble constant significant?

Answer 25

It allows scientists to take accurate measurements of the Universe

Question 26

Describe Hubble’s law in a sentence

Answer 26

How fast a galaxy moves is proportional to its dsitance

Question 27

What are quasars?

Answer 27

Astronomical objects with high luminosity found in the centre of some galaxies and powered by gas spiralling at high velocity in a supermassive black hole

Question 28

What is special about quasars?

Answer 28

Brightest objects in the universe

Question 29

What is the temperature of CMBR?

Answer 29

2.7 K

Question 30

What kind of matter we know about could make up what we think might be dark matter

Answer 30

Dark dust, black holes, brown dwarfs, neutrinos

Question 31

Why do cosmologists believe dark matter and dark energy exist?

Answer 31

The expansion of the universe should’ve decreased after the Big Bang but it is increasing, which is evidence of some other force at play

Question 32

What is X ray used to observe?

Answer 32

Effects of fast moving particles under a strong gravitational force that surrounds a black hole

Question 33

Which part of the Sun has the highest temperature?

Answer 33

Corona

Question 34

Which type of telescope is only found on satellites orbiting the Earth?

Answer 34

X ray