NATS 1750
Test #1
A Review
by
NATS 1750 Tutorial Leader
Patrick Sheese
Test results
1. When comparing the ages of the Universe and the Solar System, the
Universe is about
(a) a million times older
(b) 300 times older
(c) 100 times older
(d) 3 times older
(e) twice as old
Age of the universe? ~ 15 billion years
Age of the solar system? ~ 5 billion years (~ 4.5 billion years)
Universe age / solar system age = 15 billion / 5 billion
=3
Test results
2. After the Big Bang the hydrogen and helium formed within about
(a) one microsecond
(b) a few minutes
(c) 1 billion years
(d) 1,000 million years
(e) both (c) and (d) above
Test results
3. Ozone, O3, is important in Earth's atmosphere because
(a) it kills bacteria
(b) it is produced as a result of the photolysis of water vapour by sunlight
(c) it absorbs harmful UV radiation from the Sun and heats the stratosphere
(d) it absorbs harmful IR radiation from the Sun and heats the thermosphere
(e) both (c) and (d) above
Test results
4. The percentage of nitrogen (N2) in air today is about
(a) 1%
(b) 8%
(c) 80%
(d) 20%
(e) the same as O2
Test results
5. The molecular nitrogen, N2, in our atmosphere today came from:
(a) the remnants of Earth’s secondary atmosphere
(b) photolysis of water by sunlight
(c) evaporation of N2 from the oceans
(d) Earth’s primary atmosphere
(e) emission of N2 from uranium mines
Test results
6. If we go up in the atmosphere the temperature
(a) increases with height in some regions and decreases with height in other
regions
(b) decreases with height
(c) is about one millionth of its surface value at 90 km
(d) decreases by a factor of 10 about every 15 km
(e) none of the above
Test results
7. The pressure at the surface of Earth is 1000 millibar (mb). If the pressure
halving height is 6 km, what is the pressure outside a jet flying at 12,000
metres?
(a) 500 mb
(b) 250 mb
(c) 250 bar
(d) 250 minibars
(e) both (b) and (d)
Height (km)
Pressure (mb)
0
1000
6
500
12 ( = 12,000 m )
250
Test results
8. Most of the water vapour (H2O) in the atmosphere resides in the
(a) mesosphere
(b) stratosphere
(c) troposphere
(d) thermosphere
(e) hydrosphere
Test results
9. The highest temperatures in the atmosphere are found
(a) in the thermosphere
(b) in the summer mesopause
(c) above Greenland at night
(d) at the surface near the equator
(e) in the stratosphere
Test results
10. The hottest region of the Sun is:
(a) the Core
(b) the Convection Zone
(c) the Thermal Zone
(d) the Photosphere
(e) the Chromosphere
Test results
11. As altitude increases the pressure decreases by about
(a) 6 millibar per kilometer
(b) 1 candybar every 6 kilometers
(c) a factor of two every 6 kilometers
(d) a factor of two every 12 kilometers
(e) both (b) and (c)
Test results
12. Which of the following statements are true?
(a) gamma rays have lower frequencies than X-rays.
Æ
(b) UV radiation has lower frequencies than IR radiation. Æ
(c) Blue light has a longer wavelength than Red light.
Æ
(d) all of the above.
Æ
(e) none of the above
Æ
FALSE
FALSE
FALSE
FALSE
TRUE!
Test results
13. A radio station broadcasts on the FM band using a wavelength of 1.0
metre. What is the frequency of the radio signal?
(a) 10 MHz
(b) 100 MHz
(c) MIX-FM
(d) 680 NEWS
(e) 300 MHz
c = λν
3 x10 8 m / s
∴ν = =
= 3 x10 8 s −1 = 300 MHz
λ
1m
c
Test results
13. A radio station broadcasts on the FM band using a wavelength of 1.0
metre. What is the frequency of the radio signal?
(a) 10 MHz
(b) 100 MHz
(c) MIX-FM
(d) 680 NEWS
(e) 300 MHz
c = λν
3 x10 8 m / s
∴ν = =
= 3 x10 8 s −1 = 300 MHz
λ
1m
c
Test results
14. A radio station broadcasts on the AM band using a frequency of 300 kHz.
What is the wavelength of the radio signal?
(a) 300,000 Hz
(b) 1 km
(c) 300 m
(d) 1000 m
(e) both (b) and (d)
c = λν
3 x10 8 m / s
∴λ = =
= 1000 m = 1 km
5
ν 3 x10 Hz
c
Test results
15. Regarding the emission of radiation from any material body which of the
following is true.
(a) A hotter body absorbs less energy than a colder body
(b) The hotter the body the shorter the wavelength of its maximum radiated
energy
(c) A colder body radiates more energy than a hotter body
(d) Objects that are good absorbers of radiation are poor emitters of radiation
(e) Both (a) and (b)
Test results
16. How much more energy would a 9,000 °K star radiate than a 4,500 °K star
if they were both the same size?
(a) twice as much
(b) 4 times as much
(c) 32 times less
(d) 16 times less
(e) 16 times more
4
Ratio of energy =
5.7 x10 8 (9000) 4  9000 
4
=
=
2
= 16


8
4
5.7 x10 (4500)
 4500 
Stefan-Boltzmann law
Test results
17. How much more energy would an ‘On’ stove plate at 627 °C radiate than
an ‘Off’ stove plate at a room temperature of 27 °C
(a) 3 times more
(b) 9 times more
(c) about 23 times more
(d) 81 times more
(e) 600 times more
Need to convert temperatures into degrees Kelvin Æ 627 oC + 273 = 900 K
Æ 27 oC + 273 = 300 K
4
5.7 x10 8 (900) 4  900 
4
=
=
3
= 81
Ratio of energy =


8
4
5.7 x10 (300)
 300 
Test results
18. The region of the Sun that we can normally only see during an eclipse is
the
(a) Radiation zone
(b) Core
(c) Convection zone
(d) Corona
(e) Photosphere
Test results
19. If Ontario uses 2500 Megawatts (MW) of hydro power on a hot July
afternoon, how many Joules per second is that?
(a) 250,000,000 watts
(b) 250,000,000 Joule/s
(c) 2.5 x 109 Joule/s
(d) 2.5 x 108 Joule/s
(e) both (b) and (d)
2500 MegaWatts = 2500 x 106 Watts
= 2.5 x 109 Watts
= 2.5 x 109 Joule/s
Test results
20. The annual number of observable Sunspots varies with a period of how
many years?
(a) 27 at the Sun’s equator
(b) 11
(c) 33 near the Sun’s poles
(d) 22
(e) both (a) and (c)
Test results
21. Solar Flares enhance the Solar Wind and create
(a) Tsunamis
(b) Tidal waves
(c) The Northern Lights
(d) Earthquakes
(e) both (a) and (b)
Test results
22. The Sun consumes about 600 million tonnes of Hydrogen each second
and creates 596 million tonnes of Helium, the missing 4 million tonnes are
converted into energy according to Einstein’s famous E=mc2. What
percentage of the Hydrogen mass consumed is converted into energy
(a) about 4%
(b) about 40%
(c) about 0.7%
(d) about 7%
(e) about 59.6%
Percentage = ( amount converted / total mass ) x 100%
= ( 4 million tonnes / 600 million tonnes ) x 100%
= ( 0.006666666666…) x 100%
= 0.7 %
Test results
23. If the Sun consumes about 2x1016 tonnes of Hydrogen per year and has
about 150 x1025 tonnes of Hydrogen to burn, it could last for about
150 x1025 / 2x1016 years at the current rate, i.e.
(a) 75 billion years
(b) 7.5 x1010 years
(c) 75,000 years
(d) 7.5 zellion years
(e) both (a) and (b)
(150 x 1025) / (2 x 1016) = 75 x 109 years Æ 75 billion years
= 7.5 x 1010 years
Test results
When Steve MacLean went up on the Space Shuttle last month the
temperatures outside his Space Shuttle would have initially Q24
decreased with height as he travelled upwards through the Q25
Troposphere. But when he reached the Q26 Tropopause, where
most jets cruise, the temperatures would have started to increase
again as he entered the Q27 Stratosphere. After reaching the top
of the Q27 Stratosphere at about 50 km above Earth he passed
through the Q28 Stratopause and entered the Q29 Mesosphere
where once again temperatures decreased with height. He then
passed through the coldest region on Earth, the Q30 Mesopause,
before entering the very hottest region of Earth’s atmosphere, the
Q31 Thermosphere, where temperatures can get as high as about
Q32 1800 °K or about Q33 1500 °C at solar maximum - the
difference between °K and °C being about 300°. Since it is was so
hot up there Steve went far a wee space walk one day.