Q27.The frequency of a car horn encountered a change from 400 Hz to 500 Hz . When the car approaches a vertical wall. If the speed of sound is 330 m s−1 . Then the speed of car is ___ km h−1 .
What This Question Tests
This question involves a double Doppler effect scenario where a moving car acts as a source approaching a stationary wall, and then the reflected sound is heard by the car's driver.
Concepts Tested
Formulas Used
f' = f_0 * (v_sound - v_observer) / (v_sound - v_source)
f_reflected = f_source * (v_sound + v_car) / (v_sound - v_car)
📚 NCERT Sections This Tests
10.3 — (A) The Refractive Index Of Glass Is 1.5. What Is The Speed Of Light In
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10.3 (a) The refractive index of glass is 1.5. What is the speed of light in glass? (Speed of light in vacuum is 3.0 × 108 m s–1) (b) Is the speed of light in glass independent of the colour of light? If not, which of the two colours red and violet travels slower in a glass prism?
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14.6 Reflection of waves some cork pieces on the disturbed surface, it is seen that
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10.1 Monochromatic light of wavelength 589 nm is incident from air on a water surface. What are the wavelength, frequency and speed of (a) reflected, and (b) refracted light? Refractive index of water is 1.33.
📋 Question Details
- Chapter
- Waves & Sound
- Topic
- Doppler effect for sound waves
- Year
- 2021
- Shift
- 20 Jul Shift 1
- Q Number
- Q27
- Type
- Numerical
- NCERT Ref
- Class 11 Physics Ch 15: Waves
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