\(4.0~\text{gm}\) of gas occupies \(22.4~\text{litres}\) at NTP. The specific heat capacity of the gas at a constant volume is  \(5.0~\text{JK}^{-1}\text{mol}^{-1}.\) If the speed of sound in the gas at NTP is \(952~\text{ms}^{-1},\) then the molar heat capacity at constant pressure will be: (\(R=8.31~\text{JK}^{-1}\text{mol}^{-1}\)) 

Sound waves travel at \(350\) m/s through warm air and at \(3500\) m/s through brass. The wavelength of a \(700\) Hz acoustic wave as it enters brass from warm air:
 

The time of reverberation of a room \(A\) is one second. What will be the time (in seconds) of reverberation of a room, having all the dimensions double those of room A?

1. 2

2. 4

3. $\frac{1}{2}$

4. 1