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PRACTICE：Physics Unit33: Astrophysics and Cosmology
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 Author: physics    Total Marks: 24 mks  Marks Awarded: _____________

User Name: No Login  Start Time: 23年05月02日 09:42  Switch to Whole-Paper Mode

Mark Problem
1#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The appearance of the great range of brightnesc 4/ :k 4qyr3ovfhh8hls among stars is due to

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Mark Problem
2#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The absolute luminosity for most stars depends on they ;yjcvih u *wum.hs(7y:9;ra

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Mark Problem
3#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Four different main-sequence stars are covgs7z lblj3b:u:)4 or lored blue, orange, red, and yellow. What is their rank from coolest to hottezv3b 74:gous b:ljlr )st?

Correct Answer:    
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Mark Problem
4#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  A Hertzsprung-Russell diagraqtc:1bn+2hta b: s q4tm shows stars on a plot of

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Mark Problem
5#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  A white dwarf star with a mass equal to that of the Sun is abof ssaxh43 e(e(ut the size of

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Mark Problem
6#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Chandrasekhar limif*hvegi: k b0aj+ h4gb9: 4hrat of stellar mass (below which a star will collapse into a white dwarfv9f0j::e gkar+igh bhbh4 4* a) is, if the mass of our Sun is M, about

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Mark Problem
7#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Supernovas are thought to always resulta32 ;/jqyh ps0tq8h no;krj z. in

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Mark Problem
8#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Black holes

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Mark Problem
9#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Pulsars are rapidly spinnink cq) nysnahf2-rb6 +6g

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Mark Problem
10#
 
Free-Response ( 1.0 marks) Whole-Paper View Save Problem  
State Einstein's principle of equival 8ux,8yayf ; wy3s0aylence.
Correct Answer:    

Mark Problem
11#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Schwarzschild rak ve tk2xua ::c75/vnxdius of a black hole is that radial distance from the center of a sphere within which not even light can escape. It was first disco 5xxck2ne:vatku v7:/ vered mathematically by Schwarzschild in 1916 after Einstein published his general relativity theory. It can be calculated from a star's mass M as: $R = 2GM/c^2$. Take the radius of both stars A and B as the Schwarzschild radius. If the mass of star A is twice as much as the mass of star B, the average density of star A, compared to star B will be

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Mark Problem
12#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  When a distant source emits lpng3i m qkq9v4:t 4hm cbo*:zuoo,,w*ight of a particular wavelength in the visible, and the source is moving away from us, the color of the light appears to us to be shb, 4*m3tvoqq* okgiuh:nz4m9wpo:, cifted toward the

Correct Answer:    
Mark Problem
13#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The cosmic background radiation corresponds to dzi5fdw/2 *d ua temperature of about

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Mark Problem
14#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Sun has apparent brightness at :t wsg7f3:g sj1ex0aj fgt71vEarth ($1.5 \times 10^{8} \; km$ away) of B. What would be the apparent brightness of the Sun at Pluto, which is $6.0 \times 10^{9} \; km$ from the Sun?

Correct Answer:    
Mark Problem
15#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  A star has absolute luminosity equal to that of thr3klg6h e d qdgi, zxey6)n5.+e Sun ($1.5 \times 10^{8} \; km$ from the Earth) but is 10 pc away from the Earth. By what factor will it appear dimmer than the Sun?

Correct Answer:    
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Mark Problem
16#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Earth's orbit has i:a)hd h l6av(a mean radius of $1.5 \times 10^{8} \; km$. Over a six-month period, the apparent position of a particular star varies by $0.00014^{\circ}$ due to parallax. How distant is the star, in km?

Correct Answer:    
Mark Problem
17#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Earth's orbit has a 7xbodu(o mbta: q2g49u*rua; mean radius of $1.5 \times 10^{8} \; km$. Over a six-month period, the apparent position of a particular star varies by $0.00014^{\circ}$ due to parallax. How distant is the star, in ly? (1 ly = $9.46 \times 10^{15} \; m$)

Correct Answer:    
Mark Problem
18#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  What is the parallax angle for Proxima Centauri, which is Earth's nearest svv2 5s a 8.gk(4ahxhvftar at aafgv8hk5 svh (4.x 2v4.3 ly?

Correct Answer:    
Mark Problem
19#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The apparent brightness of auovirfoe09 yf2ofr9/ w73rz4 star is $1.0 \times 10^{-12} \; W/m^{2}$ and the peak wavelength is 600 nm. Estimate its distance from us.

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Mark Problem
20#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  It can be shown that the approximate age of the universe is 1/H, whel4bp 0/3f8nh4 xdtsjey;,t nsz- 05o:lsrgewre H is the Hubb sdfgy4rlt; 48 n:z5 e-xsjn/olp03bh 0etws,le constant. Taking H = 20 km/s/Mly, estimate the age of the universe, in years.

Correct Answer:    
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Mark Problem
21#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  If a galaxy is moving de7w ics w8t03away from us at 1.0% of the speed of light, how far away isi7wdec8ws0 t 3 it from us?

Correct Answer:    
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教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
Mark Problem
22#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Estimate the speed of a galaxy that is 10 billion light-e hb)d a15mj, ,h.trhwyears away.

Correct Answer:    
Mark Problem
23#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Estimate the observed wavelength for the 656 nm line in the spectrum of o qfgv:+1jq2pb tz 4f1a star which i4 2jzof1 q bp+ft1qv:gs 100 million light-years from us.

Correct Answer:    
Mark Problem
24#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  About 1 ms after the Big Bang, the temperature of theejrq 0g/q,i)a universe was about 1013 K. What energy (in eV) does this i aq)/g,jqe r0correspond to?

Correct Answer:    
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    Total:24 mks Pass:14.4 mks Duration:Unlimited
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