Physics
A man playing a flute is able to produce notes of different frequencies. If he closes the holes near his mouth, will the pitch of the note produced, increase or decrease? Give a reason.
Related Questions
The diagram below shows a light source P embedded in a rectangular glass block ABCD of critical angle 42°. Complete the path of the ray PQ till it emerges out of the block. [Write necessary angles.]
![The diagram below shows a light source P embedded in a rectangular glass block ABCD of critical angle 42°. Complete the path of the ray PQ till it emerges out of the block. [Write necessary angles.] ICSE 2019 Physics Solved Question Paper.](https://cdn1.knowledgeboat.com/img/abp10/5/icse-2019-physics-question-paper-solved-2e-1200x730.png)
(i) If the lens is placed in water instead of air, how does it's focal length change?
(ii) Which lens, thick or thin has greater focal length?
The specific heat capacity of a substance A is 3,800 J kg-1K-1 and that of a substance B is 400 J kg-1K-1. Which of the two substances is a good conductor of heat? Give a reason for your answer.