Question

Assertion :Whispering chambers are rooms with special acoustic properties. Some whispering chambers are built in the shape of an ellipse. Reason: When conversation occurs near one focus of the ellipse the sound waves are reflected from the walls to the other focus allowing someone positioned at the other focus to eavesdrop on the conversation.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

A whispering gallery is most simply constructed in the form of a circular wall, and allows whispered communication from any part of the internal side of the circumference to any other part. The sound is carried by waves, known as whispering-gallery waves, that travel around the circumference clinging to the walls

The gallery may also be in the form of an ellipse or ellipsoid,[4] with an accessible point at each focus. In this case, when a visitor stands at one focus and whispers, the line of sound emanating from this focus reflects directly to the focus at the other end of the gallery, where the whispers may be heard. In a similar way, two large concave parabolic dishes, serving as acoustic mirrors, may be erected facing each other in a room or outdoors to serve as a whispering gallery

Reason is correct explanation for assertion.

Option $A$