PHYS 1010 Final Exam (Units 8-11)
Question and answers verified to pass
2026/2027
The mass of a central black hole is always roughly 1/200 times the mass of the spherical distribution of
stars that surrounds it
a) True
b) False - correct answer ✔True
How can a black hole influence star formation?
a) It can compress surrounding gas and dust, promoting star formation or it can heat surrounding gas
and shred molecular clouds, suppressing star formation
b) It can compress surrounding gas and dust, suppressing star formation or it can heat surrounding gas
and shred molecular clouds, promoting star formation
c) It can compress surrounding gas and dust, promoting star formation or it can heat surrounding gas
and shred molecular clouds, also promoting star formation
d) It can compress surrounding gas and dust, suppressing star formation or it can heat surrounding gas
and shred molecular clouds, also suppressing star formation
e) Black holes cannot influence the formation of stars in a galaxy - correct answer ✔It can compress
surrounding gas and dust, promoting star formation or it can heat surrounding gas and shred molecular
clouds, suppressing star formation
When was the number of quasars in the universe greatest?
a) When the universe was 20% it's current age
b) At the birth of the universe
,c) At its current age
d) When the universe was 50% its current age
e) The number of quasars is not changing - correct answer ✔When the universe was 20% it's current
age
How are scientists able to know the size of an accreting black hole's accretion disk?
a) The size can be found by observing the time it takes the quasar's energy to vary
b) The size can be found by observing the behaviour of objects around the disk
c) The size can be found by observing how much matter is inside the accretion disk
d) The size can be found by knowing the size of the black hole and applying the relation that a black hole
is 1/200 times the size of its accretion disk
e) None of these answers - correct answer ✔The size can be found by observing the time it takes the
quasar's energy to vary
Quasars stands for ___________ __________ ____________ - correct answer ✔Quasi stellar objects
What have astronomers discovered about the Milky Way Galaxy?
a) That its supermassive black hold is not producing a quasar
b) That there are two giant bubbles emitting gamma rays above and below the galactic centre
c) That its supermassive black hole is producing a quasar
d) That it has two very wide jets coming from the galactic centre
e) That it has no supermassive black hole - correct answer ✔- That its supermassive black hold is not
producing a quasar
- That there are two giant bubbles emitting gamma rays above and below the galactic centre
, Observations have shown that quasars are located at the centres of galaxies
a) True
b) False - correct answer ✔True
Why are some supermassive black holes not associated with quasars?
a) Because they do not have a supply of matter
b) Because they are too old
c) Because they are not in a specific type of galaxy associated with quasars
d) Because they are too big to accrete any more matter
e) It is unknown why - correct answer ✔Because they do not have a supply of matter
Only _____________________ can account for all the properties of quasars that scientists have
observed - correct answer ✔Supermassive black holes
The luminosity of quasars can vary on time scales of:
a) Months
b) Days
c) Weeks
d) Light years
e) The luminosity of quasars does not vary - correct answer ✔- Months
- Days
- Weeks
Question and answers verified to pass
2026/2027
The mass of a central black hole is always roughly 1/200 times the mass of the spherical distribution of
stars that surrounds it
a) True
b) False - correct answer ✔True
How can a black hole influence star formation?
a) It can compress surrounding gas and dust, promoting star formation or it can heat surrounding gas
and shred molecular clouds, suppressing star formation
b) It can compress surrounding gas and dust, suppressing star formation or it can heat surrounding gas
and shred molecular clouds, promoting star formation
c) It can compress surrounding gas and dust, promoting star formation or it can heat surrounding gas
and shred molecular clouds, also promoting star formation
d) It can compress surrounding gas and dust, suppressing star formation or it can heat surrounding gas
and shred molecular clouds, also suppressing star formation
e) Black holes cannot influence the formation of stars in a galaxy - correct answer ✔It can compress
surrounding gas and dust, promoting star formation or it can heat surrounding gas and shred molecular
clouds, suppressing star formation
When was the number of quasars in the universe greatest?
a) When the universe was 20% it's current age
b) At the birth of the universe
,c) At its current age
d) When the universe was 50% its current age
e) The number of quasars is not changing - correct answer ✔When the universe was 20% it's current
age
How are scientists able to know the size of an accreting black hole's accretion disk?
a) The size can be found by observing the time it takes the quasar's energy to vary
b) The size can be found by observing the behaviour of objects around the disk
c) The size can be found by observing how much matter is inside the accretion disk
d) The size can be found by knowing the size of the black hole and applying the relation that a black hole
is 1/200 times the size of its accretion disk
e) None of these answers - correct answer ✔The size can be found by observing the time it takes the
quasar's energy to vary
Quasars stands for ___________ __________ ____________ - correct answer ✔Quasi stellar objects
What have astronomers discovered about the Milky Way Galaxy?
a) That its supermassive black hold is not producing a quasar
b) That there are two giant bubbles emitting gamma rays above and below the galactic centre
c) That its supermassive black hole is producing a quasar
d) That it has two very wide jets coming from the galactic centre
e) That it has no supermassive black hole - correct answer ✔- That its supermassive black hold is not
producing a quasar
- That there are two giant bubbles emitting gamma rays above and below the galactic centre
, Observations have shown that quasars are located at the centres of galaxies
a) True
b) False - correct answer ✔True
Why are some supermassive black holes not associated with quasars?
a) Because they do not have a supply of matter
b) Because they are too old
c) Because they are not in a specific type of galaxy associated with quasars
d) Because they are too big to accrete any more matter
e) It is unknown why - correct answer ✔Because they do not have a supply of matter
Only _____________________ can account for all the properties of quasars that scientists have
observed - correct answer ✔Supermassive black holes
The luminosity of quasars can vary on time scales of:
a) Months
b) Days
c) Weeks
d) Light years
e) The luminosity of quasars does not vary - correct answer ✔- Months
- Days
- Weeks
