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A theatre of volume $100 \times 40 \times 10m^3$ can accommodate 1000 visitors. The reverberation time of the theatre when empty is 8.5 s. If the theatre is now filled with 500 visitors, occupying the front-half seats, the reverberation time changes to 6.2 s. The average absorption coeficient of each visitor is nearly
A theatre of volume $100 \times 40 \times 10m^3$ can accommodate 1000 visitors. The reverberation time of the theatre when empty is 8.5 s. If the theatre is now filled with 500 visitors, occupying the front-half seats, the reverberation time changes to 6.2 s. The average absorption coeficient of each visitor is nearly
Updated On: Aug 15, 2024
- 0.6
- 0.5
- 0.45
- 0.7
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The Correct Option is D
Solution and Explanation
Number of visitors = 1000
Volume of theatre = $100 \times 40 \times 10\, cm^3$
In first case
Volume acquired by one visitor $ = \frac{100 \times 40 \times 10}{1000} = 40\, m^3$
Reverberation time = 8.5 s
In second case
Volume acquired by one visitor $ = \frac{100 \times 40 \times 10}{500} = 80\, m^3$
Reverberation time = 6.2 s
The average absorbtion coefficent
$ \hspace30mm \eta = \frac{40 \times 8.5}{80 \times 6.2} $
$ \hspace32mm = \frac{85}{124} \approx 0.7 $
Volume of theatre = $100 \times 40 \times 10\, cm^3$
In first case
Volume acquired by one visitor $ = \frac{100 \times 40 \times 10}{1000} = 40\, m^3$
Reverberation time = 8.5 s
In second case
Volume acquired by one visitor $ = \frac{100 \times 40 \times 10}{500} = 80\, m^3$
Reverberation time = 6.2 s
The average absorbtion coefficent
$ \hspace30mm \eta = \frac{40 \times 8.5}{80 \times 6.2} $
$ \hspace32mm = \frac{85}{124} \approx 0.7 $
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The waves that are produced when an electric field comes into contact with a magnetic field are known as Electromagnetic Waves or EM waves. The constitution of an oscillating magnetic field and electric fields gives rise to electromagnetic waves.
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