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question_answer1)
The observed wavelength of light coming from a distant galaxy is found to be increased by 0.5% as compared with that coming from a terrestrial source. The galaxy is [MP PMT 1993, 2003]
A)
Stationary with respect to the earth done
clear
B)
Approaching the earth with velocity of light done
clear
C)
Receding from the earth with the velocity of light done
clear
D)
Receding from the earth with a velocity equal to \[1.5\times {{10}^{6}}m/s\] done
clear
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question_answer2)
A star producing light of wavelength\[6000\,\,{AA}\]moves away from the earth with a speed of 5 km/sec. Due to Doppler effect the shift in wavelength will be \[(c=3\times {{10}^{8}}m/\sec )\] [MP PMT 1990]
A)
\[0.1\,\,{AA}\] done
clear
B)
\[0.05\,\,{AA}\] done
clear
C)
\[0.2\,\,{AA}\] done
clear
D)
\[1\,\,{AA}\] done
clear
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question_answer3)
If the shift of wavelength of light emitted by a star is towards violet, then this shows that star is [RPET 1996; RPMT 1999]
A)
Stationary done
clear
B)
Moving towards earth done
clear
C)
Moving away from earth done
clear
D)
Information is incomplete done
clear
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question_answer4)
Assuming that universe is expanding, if the spectrum of light coming from a star which is going away from earth is tested, then in the wavelength of light
A)
There will be no change done
clear
B)
The spectrum will move to infrared region done
clear
C)
The spectrum will seems to shift to ultraviolet side done
clear
D)
None of the above done
clear
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question_answer5)
Doppler's effect in sound in addition to relative velocity between source and observer, also depends while source and observer or both are moving. Doppler Effect in light depend only on the relative velocity of source and observer. The reason of this is [MP PET/PMT 1988]
A)
Einstein mass - energy relation done
clear
B)
Einstein theory of relativity done
clear
C)
Photoelectric effect done
clear
D)
None of these done
clear
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question_answer6)
A rocket is moving away from the earth at a speed of\[6\times {{10}^{7}}m/s\]. The rocket has blue light in it. What will be the wavelength of light recorded by an observer on the earth (wavelength of blue light = \[4600\,{AA}\] )
A)
\[4600\,\,{AA}\] done
clear
B)
\[5520\,\,{AA}\] done
clear
C)
\[3680\,\,{AA}\] done
clear
D)
\[3920\,\,{AA}\] done
clear
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question_answer7)
A spectral line\[\lambda =5000\,\,{AA}\]in the light coming from a distant star is observed as a\[5200\,\,{AA}\]. What will be recession velocity of the star
A)
\[1.15\times {{10}^{7}}cm/\sec \] done
clear
B)
\[1.15\times {{10}^{7}}m/\sec \] done
clear
C)
\[1.15\times {{10}^{7}}km/\sec \] done
clear
D)
1.15 km/sec done
clear
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question_answer8)
The apparent wavelength of the light from a star moving away from the earth is 0.01% more than its real wavelength. Then the velocity of star is [CPMT 1979]
A)
60 km/sec done
clear
B)
15 km/sec done
clear
C)
150 km/sec done
clear
D)
30 km/sec done
clear
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question_answer9)
A star emits light of\[5500\,\,{AA}\]wavelength. Its appears blue to an observer on the earth, it means [DPMT 2002]
A)
Star is going away from the earth done
clear
B)
Star is stationary done
clear
C)
Star is coming towards earth done
clear
D)
None of the above done
clear
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question_answer10)
The velocity of light emitted by a source S observed by an observer O, who is at rest with respect to S is c. If the observer moves towards S with velocity v, the velocity of light as observed will be [NCERT 1980]
A)
c + v done
clear
B)
\[c-v\] done
clear
C)
c done
clear
D)
\[\sqrt{1-\frac{{{v}^{2}}}{{{c}^{2}}}}\] done
clear
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question_answer11)
In the context of Doppler effect in light, the term ?red shift? signifies [MP PET 1994]
A)
Decrease in frequency done
clear
B)
Increase in frequency done
clear
C)
Decrease in intensity done
clear
D)
Increase in intensity done
clear
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question_answer12)
The sun is rotating about its own axis. The spectral lines emitted from the two ends of its equator, for an observer on the earth, will show [MP PMT 1994]
A)
Shift towards red end done
clear
B)
Shift towards violet end done
clear
C)
Shift towards red end by one line and towards violet end by other done
clear
D)
No shift done
clear
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question_answer13)
A star is moving away from the earth with a velocity of 100 km/s. If the velocity of light is \[3\times {{10}^{8}}m/s\] then the shift of its spectral line of wavelength\[5700\,\,{AA}\]due to Doppler's effect will be [MP PMT 1994]
A)
\[0.63\,\,{AA}\] done
clear
B)
\[1.90\,\,{AA}\] done
clear
C)
\[3.80\,\,{AA}\] done
clear
D)
\[5.70\,\,{AA}\] done
clear
View Solution play_arrow
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question_answer14)
If a source of light is moving away from a stationary observer, then the frequency of light wave appears to change because of [AFMC 1995]
A)
Doppler's effect done
clear
B)
Interference done
clear
C)
Diffraction done
clear
D)
None of these done
clear
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question_answer15)
A star emitting radiation at a wavelength of \[5000\,{AA}\] is approaching earth with a velocity of\[1.5\times {{10}^{6}}m/s\]. The change in wavelength of the radiation as received on the earth, is [CBSE PMT 1995]
A)
\[25\,\,{AA}\] done
clear
B)
Zero done
clear
C)
\[100\,\,{AA}\] done
clear
D)
\[2.5\,\,{AA}\] done
clear
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question_answer16)
A star emitting light of wavelength\[5896\,\,{AA}\]is moving away from the earth with a speed of 3600 km / sec. The wavelength of light observed on earth will [MP PET 1995, 2002]
A)
Decrease by\[5825.25\,\,{AA}\] done
clear
B)
Increase by\[5966.75\,\,{AA}\] done
clear
C)
Decrease by\[70.75\,\,{AA}\] done
clear
D)
Increase by \[70.75\,\,{AA}\] (\[c=3\times {{10}^{8}}m/\sec \]is the speed of light) done
clear
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question_answer17)
A star moves away from earth at speed 0.8 c while emitting light of frequency\[6\times {{10}^{14}}Hz\]. What frequency will be observed on the earth (in units of 1014 Hz) (c = speed of light) [MP PMT 1995]
A)
0.24 done
clear
B)
1.2 done
clear
C)
30 done
clear
D)
3.3 done
clear
View Solution play_arrow
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question_answer18)
A light source approaches the observer with velocity 0.8 c. The doppler shift for the light of wavelength \[5500\,{AA}\] is [MP PET 1996]
A)
\[4400\,\,{AA}\] done
clear
B)
\[1833\,\,{AA}\] done
clear
C)
\[3167\,\,{AA}\] done
clear
D)
\[7333\,\,{AA}\] done
clear
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question_answer19)
Light coming from a star is observed to have a wavelength of 3737 Å, while its real wavelength is 3700 Å. The speed of the star relative to the earth is [Speed of light \[3\times {{10}^{8}}m/s\]] [MP PET 1997]
A)
\[3\times {{10}^{5}}m/s\] done
clear
B)
\[3\times {{10}^{6}}m/s\] done
clear
C)
\[3.7\times {{10}^{7}}m/s\] done
clear
D)
\[3.7\times {{10}^{6}}m/s\] done
clear
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question_answer20)
In the spectrum of light of a luminous heavenly body the wavelength of a spectral line is measured to be 4747 Å while actual wavelength of the line is 4700 Å. The relative velocity of the heavenly body with respect to earth will be (velocity of light is \[3\times {{10}^{8}}m/s\]) [MP PMT/PET 1998]
A)
\[3\times {{10}^{5}}m/s\]moving towards the earth done
clear
B)
\[3\times {{10}^{5}}m/s\]moving away from the earth done
clear
C)
\[3\times {{10}^{6}}m/s\]moving towards the earth done
clear
D)
\[3\times {{10}^{6}}m/s\]moving away from the earth done
clear
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question_answer21)
The wavelength of light observed on the earth, from a moving star is found to decrease by 0.05%. Relative to the earth the star is [MP PMT/PET 1998]
A)
Moving away with a velocity of \[1.5\times {{10}^{5}}m/s\] done
clear
B)
Coming closer with a velocity of \[1.5\times {{10}^{5}}m/s\] done
clear
C)
Moving away with a velocity of \[1.5\times {{10}^{4}}m/s\] done
clear
D)
Coming closer with a velocity of \[1.5\times {{10}^{4}}m/s\] done
clear
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question_answer22)
A star is going away from the earth. An observer on the earth will see the wavelength of light coming from the star [MP PMT 1999]
A)
Decreased done
clear
B)
Increased done
clear
C)
Neither decreased nor increased done
clear
D)
Decreased or increased depending upon the velocity of the star done
clear
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question_answer23)
A star is moving towards the earth with a speed of \[4.5\times {{10}^{6}}\]m/s. If the true wavelength of a certain line in the spectrum received from the star is\[5890\,\,{AA}\], its apparent wavelength will be about \[[c=3\times {{10}^{8}}m/s]\] [MP PMT 1999]
A)
\[5890\,\,{AA}\] done
clear
B)
\[5978\,\,{AA}\] done
clear
C)
\[5802\,\,{AA}\] done
clear
D)
\[5896\,\,{AA}\] done
clear
View Solution play_arrow
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question_answer24)
Due to Doppler's effect, the shift in wavelength observed is 0.1 Å for a star producing wavelength 6000 Å. Velocity of recession of the star will be
A)
2.5 km/s done
clear
B)
10 km/s done
clear
C)
5 km/s done
clear
D)
20 km/s done
clear
View Solution play_arrow
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question_answer25)
A rocket is going away from the earth at a speed of 106 m/s If the wavelength of the light wave emitted by it be \[5700\,\,{AA}\], what will be its Doppler's shift [RPMT 1996]
A)
\[200\,\,{AA}\] done
clear
B)
\[19\,\,{AA}\] done
clear
C)
\[20\,\,{AA}\] done
clear
D)
\[0.2\,\,{AA}\] done
clear
View Solution play_arrow
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question_answer26)
A rocket is going away from the earth at a speed 0.2c, where c = speed of light. It emits a signal of frequency \[4\times {{10}^{7}}Hz\]. What will be the frequency observed by an observer on the earth [RPMT 1996]
A)
\[4\times {{10}^{6}}Hz\] done
clear
B)
\[3.2\times {{10}^{7}}Hz\] done
clear
C)
\[3\times {{10}^{6}}Hz\] done
clear
D)
\[5\times {{10}^{7}}Hz\] done
clear
View Solution play_arrow
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question_answer27)
If a star is moving towards the earth, then the lines are shifted towards [AIIMS 1997]
A)
Red done
clear
B)
Infrared done
clear
C)
Blue done
clear
D)
Green done
clear
View Solution play_arrow
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question_answer28)
When the wavelength of light coming from a distant star is measured it is found shifted towards red. Then the conclusion is [JIPMER 1999]
A)
The star is approaching the observer done
clear
B)
The star recedes away from earth done
clear
C)
There is gravitational effect on the light done
clear
D)
The star remains stationary done
clear
View Solution play_arrow
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question_answer29)
A heavenly body is receding from earth such that the fractional change in l is 1, then its velocity is [DCE 2000]
A)
C done
clear
B)
\[\frac{3C}{5}\] done
clear
C)
\[\frac{C}{5}\] done
clear
D)
\[\frac{2C}{5}\] done
clear
View Solution play_arrow
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question_answer30)
The\[6563\,\,{AA}\]line emitted by hydrogen atom in a star is found to be red shifted by\[5\,\,{AA}\]. The speed with which the star is receding from the earth is [Pb. PMT 2002]
A)
17.29 - 109 m/s done
clear
B)
4.29 - 107 m/s done
clear
C)
3.39 - 105 m/s done
clear
D)
2.29 - 105 m/s done
clear
View Solution play_arrow
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question_answer31)
Three observers A, B and C measure the speed of light coming from a source to be \[{{v}_{A}}\], \[{{v}_{B}}\] and \[{{v}_{C}}\]. The observer A moves towards the source, the observer C moves away from the source with the same speed. The observer B stays stationary. The surrounding space is vacuum everywhere. Then [KCET 2002]
A)
\[{{v}_{A}}>{{v}_{B}}>{{v}_{C}}\] done
clear
B)
\[{{v}_{A}}<{{v}_{B}}<{{v}_{C}}\] done
clear
C)
\[{{v}_{A}}={{v}_{B}}={{v}_{C}}\] done
clear
D)
\[{{v}_{A}}={{v}_{B}}>{{v}_{C}}\] done
clear
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question_answer32)
Light from the constellation Virgo is observed to increase in wavelength by 0.4%. With respect to Earth the constellation is [MP PET 2003]
A)
Moving away with velocity 1.2 ´ 106 m/s done
clear
B)
Coming closer with velocity 1.2 ´ 106 m/s done
clear
C)
Moving away with velocity 4 ´ 106 m/s done
clear
D)
Coming closer with velocity 4 ´ 106 m/s done
clear
View Solution play_arrow
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question_answer33)
It is believed that the universe is expanding and hence the distant stars are receding from us. Light from such a star will show [CPMT 2005]
A)
Shift in frequency towards longer wavelengths done
clear
B)
Shift in frequency towards shorter wavelength done
clear
C)
No shift in frequency but a decrease in intensity done
clear
D)
A shift in frequency sometimes towards longer and sometimes towards shorter wavelengths done
clear
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