Q. The sound produced by the loudspeaker has a frequency of 12002 Hz and arrives at the microphone via two different paths. The sound travels through the left tube LXM that has a fixed length. Concurrently, the sound travels through the right tube LYM, length of which can be changed by moving the sliding section. At M, sound waves coming from the two paths interfere. As length of the path LYM is changed, the sound loudness detected by the microphone changes. While sliding section is pulled out by 0.020 m the loudness changes from a maximum to a minimum. Find out the speed at which sound travels through the gas in the tube.