A source of sound is approaching an observer with speed of 30 m/s and the observer is approaching the source with a speed 60 m/s. Then the fractional change in the frequency of sound in air (330 m/s) is

A train is moving with a uniform speed of 33 m//s and an observer is approaching the train with the same speed. If the train blows a whistle of frequency 1000 Hz and the velocity of sound is 333 m//s then the apparent frequency of the sound that the observer hears is

A train is moving with a uniform speed of 33 m/s and an observer is approaching the train with the same speed. If the train blows a whistle of frequency 1000 Hz and the velocity of sound is 333 m/s, then the apparent frequency of the sound that the observer hears is

A source of sound and an observer are approaching each other with the same speed, which is equal to (1/10) times the speed of sound. The apparent relative change in frequency of source is

A source of sound and an observer are approaching each other with the same speed which is equal to (1)/(10) times the speed of sound. The apparent change in the frequency of the source is

A source is moving towards an observer with a speed of 20 m / s and having frequency of 240 Hz . The observer is now moving towards the source with a speed of 20 m / s . Apparent frequency heard by observer, if velocity of sound is 340 m / s , is