By signing in you confirm you are 18 or older, or have your parent’s or guardian’s consent.

NDA 1 2025 GAT, question 149

Topic: Physics

Q149

We hear an echo due to

  1. (a) Refraction of sound waves
  2. (b) Reflection of sound wavesCorrect answer
  3. (c) Diffraction of sound waves
  4. (d) Resonance due to sound waves

Solution.

Answer: (b) Reflection of sound waves

  1. An echo is heard when sound reflects from a sufficiently distant surface and returns to the listener after the original sound.
  2. Refraction changes propagation direction through varying media, diffraction is bending around obstacles, and resonance is enhanced vibration at a natural frequency.