Question

The time of reverberation of room A is one second. What will be the time (in seconds) of reverberation of a room, having all the dimensions double of those of room A-
A. 2
B. 4
C. $\dfrac{1}{2}$
D. 1

Answer 1

The Reverberation Time (RT) is that the time the instantaneous sound pressure level takes to decrease by 60 dB after a sound source is abruptly transitioned. RT60 is thus a commonly-used abbreviation for Reverberation Time. RT60 values vary in several positions within an area.

Complete answer:
Time of reverberation $\propto$ A V ( Sabine's formula)
Where V = volume of room and A = area of room
We know that
${\text{A}} \propto {({\text{dimension}}\,\,{\text{of}}\,{\text{room}})^2}$
${\text{V}} \propto {({\text{dimension}}\,\,{\text{of}}\,{\text{room}})^3}$
Therefore, the Area of the latest room becomes 4 times of A and Volume becomes 8 times of room A.
The time of reverberation is going to be 2 seconds.
Reverberation time is the time required for the sound to “fade away” or decay during a closed space. Reverberation reduces when the reflections hit surfaces that will absorb sound like curtains, chairs and even people. The reverberation time of an area or space is defined because the time it takes for sound to decay by 60dB.
RT60 = Reverberation Time.
V = volume of the space (feet cubed)
a = total room absorption at given frequency.
In an existing room, you'll continue to sit and measure the reverberation time employing a loud speaker and a sound level meter.

Hence, The option (A) is correct.

Note:
Describing a reverb time nearly as good or bad is essentially hooked into how you propose to use the space. As a result, general purpose auditoriums tend to separate the difference, aiming for a reverberation time between 1.5 and 2.5 seconds. Cathedral- Cathedrals are an excellent example of purposeful acoustic design.