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PRACTICE：Physics Unit33: Astrophysics and Cosmology
本Practice来源于https://webassign.org，是在线Practice的打印版，您也可以访问本平台网站(https://webassign.org/)直接在线完成(注册并登录账号后在首页左侧输入试卷号 332 即可在线作答)，，作答电子化后可随时回放，查看每题答案与详细解析，搜藏保存任意题目；教师使用本平台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。本试卷的直接作答链接 https://webassign.org/test332.html
 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 k3e7hv ooi 29mnsl 0p 4zoi)d5of brightness 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(8 um41gnfng4boe w8l most stars depends on the

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Mark Problem
3#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Four different main-sequence stars are colored blue, orange, bzs0oi7s6:eo,wh+hrn-w. s2xoj r :dred, and yellow. What is their rank from r+6sn::h7sw o2oi-who, ezj s.0rdb x coolest to hottest?

Correct Answer:    
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Mark Problem
4#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  A Hertzsprung-Russell diagram showtohfk:4ypx , 3s 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 about t +sqw1wc a.nc.alhuf6 iw31d*he size of

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Mark Problem
6#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Chandrasekhar limit of stellar mass (below which a star will collapsn m+-k)c do0khe into a white dwarf) is, if the mass of our Sun is M, aboukm o-)dch +n0kt

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Mark Problem
7#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Supernovas are thought to alek0 )fmby3;y4z hbb mx1c* 2upm oa6.eways result 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 spingmx ;+ s:a cc,g,saspwz) +n/rning

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Mark Problem
10#
 
Free-Response ( 1.0 marks) Whole-Paper View Save Problem  
State Einstein's principle ofqcg vy7*xc2e9g)jci; r f9*o a equivalence.
Correct Answer:    

Mark Problem
11#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Schwarzschild radius of a black hole is*(t1g86c:)ouk .cogu vck k ig that radial distance from the center of a sphere within which not even light can escape. It waiuo(c vtg* ggo )8:1 ckukkc.6s first discovered 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

Correct Answer:    
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Mark Problem
12#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  When a distant source emits light of a particular wavelen l-9 nuvs/ws;tgth in the visible, and the source is moving away from us, the color of the light appears t l9v/;nwuss- to us to be shifted toward the

Correct Answer:    
本Practice全部题目来源于https://webassign.org，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
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
13#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The cosmic background radiation corresponds to )lyy3bczayc;2 zu ,d,( mjbf2 a temperature of about

Correct Answer:    
本Practice全部题目来源于https://webassign.org，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
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
14#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Sun has apparent brightne6sjsd1n ( 0+le4 xpt. ijdya6kss at Earth ($1.5 \times 10^{8} \; km$ 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 9br,ph/c caf7luminosity equal to that of the 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:    
Mark Problem
16#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Earth's orbit has a mean radiu r5 2dln4yj,qrs 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.+pe9kc4cb9oj ,2ai ez,aoy(+dcmrf 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 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 ang4zbog.ao5j vd -t(a+dle for Proxima Centauri, which is Earth's nearest star at 4.3 loaavd-do.4 g (b5+tj zy?

Correct Answer:    
Mark Problem
19#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The apparent brightness ofy8wok n bx8awzx;75-d a 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, where H is the ht. p fdmsbk8t7: .(imHubble constant. Taking H = 20 km/s/Mly, estimate the age of the unived:tkf h m(i87bs.tpm. rse, in years.

Correct Answer:    
Mark Problem
21#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  If a galaxy is moving away from us at 1h qb5t::qq82 1ic gvva1urbl1.0% of the speed of light, how far away is it fro1tra v1 chq5:i l1u:2qgvbq b8m us?

Correct Answer:    
Mark Problem
22#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Estimate the speed of a galaxy that i0l-( *2yk zibkxpj8p os 10 billion light-years away.

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Mark Problem
23#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Estimate the observed wavelength for the 656 nm line in th n:sn332hd 5yz 5z5o pqevto8ke spectrum of a star which is 100 million light-yeaev 5 8dy32th:z5qo5kpn s3onzrs from us.

Correct Answer:    
Mark Problem
24#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  About 1 ms after the Binweo6 /o l ,k:xbkfut7j)( irv 1l1*kwg Bang, the temperature of the universe was about 1013 K. What energy (in eV) doel/w)1t7bekkljx, k(vfoiw *ru1n:o 6s this correspond to?

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