Answer:
The human ear is not sensitive to every frequency of sound, rather, our hearing range is from 20Hz to 20,000Hz. This means sound frequencies outside this range are not audible to the human ear, which is why not every sound produced is heard. This is quite a blessing because if we could hear every vibrating body, then our ears would never stop listening: we won't be able to distinguish 'important sounds' from unimportant ones, rendering our ears effectively useless. Perhaps this is why we have a hearing range in the first place: sounds of our friends and our foes lie in 20Hz-20kHz range.
Answer:
A) 58 degree
Explanation:
When unpolarized light passing through first polarizer then the intensity of light becomes half as it will get polarized
So let say the intensity of unpolarized light is "Io" then after passing through first polarizer the intensity will become half
Now when this polarized light passing through another polarizer then the intensity of light is given by Malus law
As per Malus law if the angle between two polarizer axis is inclined at some angle
then it is given as




<span>Clear cutting has a similar effect as controlled burning of a forest is True.
True </span>