What is the principle behind the working of photoconductive cell?

What is the principle behind working of sonar ?

What is the principle behind starch test?

Answer the following questions : What is the principle behind the working of a satellite launch vehicle?

What is the principle of working of a rocket?

What is the principle behind the working of a transformer ? Mention any two sources of energy loss in transformer

What is the principle of working of a rocket ?

What is the principle of the working of the human eye?