Question

Repetition of original sound heard after reflection is called

• A. resonance
• B. echo
• C. dissonance
• D. sonar

Answer 1

The correct option is B

echo

Explanation of correct answer:

(B) Echo:

1. It is a common experience that when we shout in front of a high mountain or a deep well or in a big empty hall, we hear our sound back after a few seconds.
2. This is known as echo.
3. An echo is the repetition of the original sound heard after the sound is reflected from a distant, dense and rigid object (such as a high building, cliff, etc.).

Explanation of incorrect answer:

(A) Resonance:

1. It is the relatively large selective response of an object or a system that vibrates in step or phase, with an externally applied oscillatory force.
2. Resonance was first investigated in acoustical systems such as musical instruments and the human voice.

(C) Dissonance:

1. A combination of two (or more) tones of different frequencies results in a musically displeasing sound.

(D) Sonar:

1. The word 'sonar' refers to Sound Navigation and Ranging.
2. It is an instrument used to find the depth of a sea or investigate underwater objects like submarines and shipwrecks.
3. It is based on the principle of reflection of sound.

Hence, the correct answer is (B) Echo.