Two sirens situated one kilometer apart are producing sound of frequency 330 Hz. An observer starts moving from one siren to the other with a speed of 2 m/s. If the speed of sound be 330 m/s, what is the beat frequency heard by the observer ____.
A source of sound is traveling with a velocity 40 km / hour towards observer and emits sound of frequency 2000 Hz. If velocity of sound is 1220 km / hour, then what is the apparent frequency heard by an observer ____.
A source of sound and listener are approaching each other with a speed of 40 m/s. The apparent frequency of note produced by the source is 400 cps. Then, its true frequency (in cps) is (velocity of sound in air = 360 m/s) ____.
A siren emitting sound of frequency 500 Hz is going away from a static listener with a speed of 50 m/s. The frequency of sound to be heard, directly from the siren, is ____.
A man sitting in a moving train hears the whistle of the engine. The frequency of the whistle is 600 Hz ____.
the apparent frequency as heard by him is smaller than 600 Hz
the apparent frequency is larger than 600 Hz
the frequency as heard by him is 600 Hz
None of the above
A source of sound of frequency 500 Hz is moving towards an observer with velocity 30 m/s. The speed of sound is 330 m/s. the frequency heard by the observer is ____.
A whistle of frequency 500 Hz tied to the end of a string of length 1.2 m revolves at 400 rev/min. A listener standing some distance away in the plane of rotation of whistle hears frequencies in the range (speed of sound = 340 m/s) ____.
436 to 586
426 to 574
426 to 584
436 to 674
If source and observer both are relatively at rest and if speed of sound is increased then frequency heard by observer will ____.
CAN NOT BE PREDICTED
WILL NOT CHANGE
A source and an observer move away from each other with a velocity of 10 m/s with respect to ground. If the observer finds the frequency of sound coming from the source as 1950 Hz, then actual frequency of the source is (velocity of sound in air = 340 m/s) ____.
A source emits a sound of frequency of 400 Hz, but the listener hears it to be 390 Hz. Then ____.
the listener is moving towards the source
the source is moving towards the listener
the listener is moving away from the source
the listener has a defective ear