What is musical scale?

Define reverberation time?

An observer moves towards a stationary source of sound with a velocity one-fifth of the velocity of sound. What is the percentage increase in the apparent frequency?

Tube A. has both ends open, while B has on end closed otherwise the two tubes are identical. What is the ratio of fundamental frequency of the tubes A and B?

A train moves towards a stationary observer with speed 34 m/s. The train' sounds a whistle and its frequency registered by the observer is f_1. the train's speed is reduced to 17 m/s, the frequency registered is f₂. If the speed of sound is 340 m/s, then find the ratio f_1/f_2.