Physics
In ancient India, dome shaped courts were built in forts to allow even the faintest of sounds to be heard from far away. Which statement best explains this effect?
- Dome increases the frequency of the sound so it becomes louder.
- Dome absorbs high frequency sound and re-emits it at a high amplitude.
- Dome focuses the reflected sound and multiple reflected waves reinforce at listener's position.
- Dome traps air thereby increasing air pressure resulting in amplification of sound.
Answer
Dome focuses the reflected sound and multiple reflected waves reinforce at listener's position.
Reason — In dome-shaped courts, sound waves produced at one point undergo multiple reflections from the curved surface of the dome.
Due to the geometry, these reflected waves tend to converge or focus at specific locations, so several waves reach the listener together which causes reinforcement of sound, making even faint sounds clearly audible over a distance.
Related Questions
The diagram shown below depicts a displacement time graph of particle a wave travelling with speed 20 m/s.
The frequency of the wave is :
- 50 Hz
- 33.3 Hz
- 100 Hz
- 1000 Hz
A girl claps in a classroom but is unable to hear an echo. Which option best explains the reason for the same ?
- There is no reflection of sound from the walls.
- Sound waves are completely absorbed by the walls.
- Echo returns in less than 0.1 s.
- Echoes require sounds of ultrasonic frequency.
Assertion (A): Sound waves can travel in vacuum, but light waves cannot.
Reason (R): Light is an electromagnetic wave, but sound is a mechanical wave .
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true and R is not the correct explanation of A.
- assertion is false but reason is true.
- assertion is true but reason is false.
Assertion (A): The speed of sound in a gas increases with an increase in humidity.
Reason (R): Density of a gas decreases with increase in humidity.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true and R is not the correct explanation of A.
- assertion is false but reason is true.
- assertion is true but reason is false.