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Quiz sobre UNIT 2 , criado por maisy r em 06-02-2019.

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UNIT 2

Questão 1 de 25

1


Which of these layers of the Sun is the coolest?

Selecione uma das seguintes:

  • Corona

  • Photosphere

  • Transition zone

  • Chromosphere

  • Convection zone

Explicação

Questão 2 de 25

1

A sudden, violent disruption (usually found near a sunspot) that releases an enormous amount of energy in almost all wavelengths in a very short amount of time is called a solar

Selecione uma das seguintes:

  • prominence

  • aurora

  • facula

  • filament

  • flare

Explicação

Questão 3 de 25

1


From Earth, we can observe individual sunspots moving across the face of the Sun as the Sun rotates. Because the Sun is large, the time it takes for them to move from the eastern edge of the Sun's disk over the western edge, from our viewpoint, is about

Selecione uma das seguintes:

  • two weeks.

  • 2 months.

  • 5.5 years.

  • 1 week.

  • a month.

Explicação

Questão 4 de 25

1


From the outside moving in towards the centre of the Sun, which sequence of layers is in the correct order for the structure of the Sun?

Selecione uma das seguintes:

  • corona, radiative zone, photosphere, core

  • photosphere, chromosphere, radiative zone, core

  • chromosphere, radiative zone, convective zone, core

  • transition zone, photosphere, chromosphere, radiative zone

  • chromosphere, convective zone, radiative zone, core

Explicação

Questão 5 de 25

1


The Sun goes through a regular cycle of activity on its surface due to changes in its complex magnetic field. This cycle can be tracked by watching for changes in the number of sunspots that appear on its photosphere. The activity is at a maximum when the sunspot number is at its highest. On average, how long does the cycle last before it repeats itself?

Selecione uma das seguintes:

  • about 76 years

  • between 25 and 35 days

  • 365.25 days

  • about 11 years

  • about seven years

Explicação

Questão 6 de 25

1

Stellar spectra tell us that ________ is the second most abundant element in the Sun.

Selecione uma das seguintes:

  • iron

  • hydrogen

  • oxygen

  • helium

  • carbon

Explicação

Questão 7 de 25

1


As a direct result of the nuclear reaction process in the central core of the Sun, the only EM radiation released into the outer portions of the core and the radiative layer immediately surrounding it is

Selecione uma das seguintes:

  • X-rays

  • UV rays

  • visible light

  • gamma rays

  • infrared rays

Explicação

Questão 8 de 25

1


The Sun's photosphere layer is composed of convecting bubbles of charged gas particles.

Selecione uma das seguintes:

  • True

  • False

Explicação

Questão 9 de 25

1


Because of the tremendous pressure/density present in the Sun's radiative zone, photons of light trying to leave the core of the Sun take about __________________________ to travel through the radiative zone to the next outer solar layer.

Selecione uma das seguintes:

  • 12,000 years

  • 8 months

  • 12 weeks

  • 200,000 years

  • 600 years

Explicação

Questão 10 de 25

1


In the nuclear fusion process, two protons (from hydrogen atoms) can only fuse in a region where the minimum temperature is greater than about ___________________.

Selecione uma das seguintes:

  • 200 million K.

  • 15 million K

  • 1,500,000 K.

  • 12 million K.

  • 100 million K.

Explicação

Questão 11 de 25

1


The final step in transporting energy to the surface of the Sun is via convection.

Selecione uma das seguintes:

  • True

  • False

Explicação

Questão 12 de 25

1


Helioseismology has allowed scientists to develop a fairly sophisticated model of the internal structure of the Sun. This was possible through the study of ________________________ which astronomers began in the 1960's.

Selecione uma das seguintes:

  • changes in solar x-ray flares

  • coronal mass ejections

  • magnetic field line reconnection events

  • variations in the solar flux - the overall solar energy output
    doppler-shifted absorption lines in the solar spectrum

  • doppler-shifted absorption lines in the solar spectrum

Explicação

Questão 13 de 25

1


The constantly changing markings on the surface of the Sun which are actually the tops of hot convective cells rising in the photosphere are known as...

Selecione uma das seguintes:

  • granules

  • flares

  • faculae

  • spicules

Explicação

Questão 14 de 25

1


What causes the cycle of solar activity?

Selecione uma das seguintes:

  • Changes in magnetic fields due to rotation and upwellings from deep in the solar interior by way of conveyor belts.

  • Cyclical changes in the Sun's fusion rate due to sinking and mixing of heavier elements from outer core material.

  • The gravitational collapse of helium atoms towards the core.

  • The cyclical build up and release of energy created through the radioactive decay of hydrogen isotopes in the region surrounding the core.

  • A cyclical build up and oxidation of carbon in the core.

Explicação

Questão 15 de 25

1


The charged particles blasting out of the Sun's atmosphere and traveling in the solar wind travel at almost 300,000 km/s.

Selecione uma das seguintes:

  • True

  • False

Explicação

Questão 16 de 25

1

Sunspots contain 2 zones - a cooler central umbra and a warmer outer penumbra.

Selecione uma das seguintes:

  • True

  • False

Explicação

Questão 17 de 25

1

The strongest magnetic fields in the photosphere lie near

Selecione uma das seguintes:

  • prominences

  • flares

  • sunspots.

  • auroras

  • granules

Explicação

Questão 18 de 25

1


The Sun sheds about _____________________ tonnes of particles each second in a continuous flow out of its outer atmosphere (known as the "solar wind").

Selecione uma das seguintes:

  • 1,000

  • 5 million

  • 20,000

  • 1 million

  • 400,000

Explicação

Questão 19 de 25

1

Which is the net result of the proton-proton chain?

Selecione uma das seguintes:

  • 4 protons → 2 helium 2 + 2 positrons + ultraviolet radiation

  • 6 protons → 2 helium 4 + 3 positrons + 3 neutrinos + gamma rays

  • 4 protons → 1 helium 4 + a positron + a neutrino + gamma rays

  • Correct 4 protons → 1 helium 4 + 2 neutrinos + gamma rays

Explicação

Questão 20 de 25

1

While the photosphere produces chiefly visible light, most coronal energy is in the form of

Selecione uma das seguintes:

  • radio waves

  • X-rays.

  • gamma rays.

  • infrared radiation.

  • ultraviolet light.

Explicação

Questão 21 de 25

1


Who was the first scientist (1887) to notice that the sun's regular activity/sunspot cycle goes through occasional slumps, where for a number of years, there are significantly lower numbers of sunspots than normal - even in years of supposed maximum activity?

Selecione uma das seguintes:

  • E.W. Maunder

  • Gustav Sporer

  • Alexander Friedmann

  • Vesto Slipher

  • Joseph von Fraunhofer

Explicação

Questão 22 de 25

1

Astronomers estimate that every second the sun produces an amount of energy equivalent to the explosion of about....

Selecione uma das seguintes:

  • 100 billion 1-megaton nuclear bombs

  • 500 million 1-megaton nuclear bombs

  • 250 million 1-megaton nuclear bombs

  • 400 billion 1-megaton nuclear bombs

Explicação

Questão 23 de 25

1


How often does the Sun's entire magnetic field flip in its orientation?

Selecione uma das seguintes:

  • about once every 18 months

  • once every 176 years

  • once a month

  • once every 22 years

  • once every 11 years

Explicação

Questão 24 de 25

1


In the 1970s, astronomers discovered that many of the expected neutrinos supposedly emitted by the Sun were not being detected. A theory evolved that they were oscillating between three states as they travelled away from the Sun. What are the three states that a neutrino can take?

Selecione uma das seguintes:

  • muon, gluon, and electron

  • gluon, sigma, and tau

  • tau, electron, gluon

  • electron, tau, and muon

  • tau, sigma and muon

Explicação

Questão 25 de 25

1


In order to produce the 4 x 1026 watts of energy that it radiates, the Sun, through nuclear fusion, must convert _______________________ tonnes of hydrogen into helium each second.

Selecione uma das seguintes:

  • 20 million

  • 600 million

  • 1.88 million

  • 1.2 billion

Explicação