ICSE − Q & A

Can anyone provide a brief reason for why musical instruments are provided with a sound box? Is resonance required here

I have already asked some people , but I'm asking again: can it be possible for you to confirm it with some board corrector(maybe your teacher):
1) In boards is group 1 compulsory or it is english and best 4 (i think it's the latter, one of my teacher said it's the former)
2) does the board give only the marksheet, or also the percentage as on the website after entering UID, we only see the marksheet.
Thank you.

Most abundant enzyme on earth?

Is the envelope format both for formal and informal letters in Hindi and is it compulsory?

It is said that ultrasonic waves of frequency more than 20kHz can travel undeviated through a long distance without getting easily absorbed in a medium. But if the frequency is high, then wavelength should be less and hence the sound wave should be easily scattered and absorbed in the medium, right?

all those who wanted envelope format check this link http://www.respaper.com/prakrutidesai/658-zip.html

Any Star Wars fan out here?

I am having problem with the sums on how to calculate the power of a lens....if it is a real image then power will be negative & if a virtual image then positive...is it right??

physics paper: http://www.respaper.com/ansh_cr7/4705-zip.html
please help me in question 2.d

Can somebody please send the solution for the 5th numerical of exercise 2D in the SELINA Concise Physics book??