Question

John is listening to a horn. When the horn and John are both at rest, the frequency of the horn is 300 Hz. If he hears a pitch of 330 Hz, there are clearly several possibilities. State which of the possibilities are correct.

1. Both can be moving and have the same speed

2. John is moving towards the horn at rest

3. The distance between John and the horn is increasing with time

4. Both can be moving in opposite directions

5. Both can be moving and have different speeds

6. John and the horn are both moving in the same direction but John is behind and moving faster than the horn

Answer 1

For this question, there are multiple possibilities of getting the desired frequency -

To get higher frequency at observer from the source frequency than there is the only way that distance of between source and receiver gets lesser.

And according to this-

Option 1 )- there is not mentioned that they both are moving towards each other. so this is wrong.

Option 2 )- John is moving towards the horn at rest i.e. that distance between both gets lesser. (Correct option)

rest options are also wrong.

Thankyou !!! Have Fun

Please Rate High.