Doppler's Effect of Light- MCQ-Basic

Doppler's Effect of Light- MCQ-Basic

Dear Readers,

Physics is an important subject in preparation for various Competitive exams. To keep a track of your preparation we have designed a small quiz of 10 Basic Level Questions on Doppler's Effect of Light.You have 10 minutes to solve the quiz, click the start timer button in order to start the timer and then click on submit button at the end to submit the quiz and view your scores and correct answers.

Q1. The observed wavelength of light coming from a distant galaxy is found to be increased by 0.5% as compared with that comparing from a terrestrial source. The galaxy is

•  Stationary with respect to the earth
•  Approaching the earth with velocity of light
•  Receding from the earth with the velocity of light
•  Receding from the earth with a velocity equal to 1.5 X 10⁶m/s

Receding from the earth with a velocity equal to 1.5 X 10⁶m/s

Q2. A star emits light of 5500 Å wavelength. Its appears blue to an observer on the earth, it means

•  Star is going away from the earth
•  Star is stationary
•  Star is coming towards earth
•  None of the above

Star is coming towards earth

Q3. A star is going away from the earth. An observer on the earth will see the wavelength of light coming from the star

•  Decreased
•  Increased
•  Neither decreased nor increased
•  Decreased or increased depending upon the velocity of the star

Increased

Q4. If the shift of wavelength of light emitted by a star is towards violet, then this shows that star is

•  Stationary
•  Moving towards earth
•  Moving away from earth
•  Information is incomplete

Moving towards earth

Q5. When the wavelength of light coming from a distant star is measured it is found shifted towards red. Then the conclusion is

•  The star is approaching the observer
•  The star recedes away from earth
•  There is gravitational effect on the light
•  The star remains stationary

The star recedes away from earth

Q6. 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

•  Shift towards red end
•  Shift towards violet end
•  Shift towards red end by one line and towards violet end by other
•  No shift

Shift towards red end by one line and towards violet end by other

Q7. 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

•  60 km/sec
•  15 km/sec
•  150 km/sec
•  30 km/sec

30 km/sec

Q8. The time period of rotation of the sun is 25 days and its radius is 7 X 10⁸m.The Doppler shift for the light of wavelength 6000 Å emitted from the surface of the sun will be

•  0.04 Å
•  0.40 Å
•  4.00 Å
•  40.0 Å

0.04 Å

Q9. A star moves away from earth at speed 0.8 c while emitting light of frequency 6 X 10¹⁴Hz . What frequency will be observed on the earth (in units of 10¹⁴Hz ) (c = speed of light)

•  0.24
•  1.2
•  30
•  3.3

1.2

Q10. A rocket is going away from the earth at a speed 0.2 c, where c = speed of light, it emits a signal of frequency 4 X 10⁷Hz . What will be the frequency observed by an observer on the earth

•  4 X 10⁶Hz
•  3.3 X 10⁷Hz
•  3 X 10⁶Hz
•  5 X 10⁷Hz

3.3 X 10⁷Hz