which sheet will you choose as a sound-reflecting surface for the experiment “laws of reflection of sound” and why?
A) A smooth wooden board
B) A thermocol sheet

Hint: Different surfaces have the tendency to absorb or reflect sound. In the experiment of “laws of reflection” a surface is used to reflect sound. If the surface can reflect most of the sound then we hear more clearly but if the surface absorbs some sound then we don’t. So we have to choose a surface for this experiment accordingly.

Complete Step By Step Answer:
Sound: is a vibration-based kind of energy that requires a medium to propagate.
Sound reflection: Sound is reflected in the same way that light is reflected when it strikes a hard (opaque) object.
Laws of Sound Reflection-
-The angle of incidence and reflection are always the same.
-All sound waves, incident, normal, and reflected, exist in the same plane.
-When sound strikes any surface, it is not only reflected but also absorbed in part by the wall's surface. As a result, the sound you hear through the pipe is determined by the nature of the wall. The reflection will be more for a smooth reflecting wall.
A thermocol sheet is soft and is porous. It will absorb some sound while a smooth wooden board will reflect most of the sound.
Hence option A) a smooth wooden board is the correct option.

Note:
A reflection of sound occurs when sound waves bounce back from the surface of a solid or liquid. Phenomena, such as Echoes and Reverberation, are caused by sound reflection.