What is polar coordinates ? Explain with the help of diagram.

What are optical fibres ? Explain with the help of diagram on what principle does it work ?

What is transcription. Explain it with the help of a diagram.

What is an electric circuit ? Explain with the help of a diagram.

What are electromagnetic waves ? Explain with the help of diagram.

What is meant by lateral inversion of an image in a plane mirror ? Explain it with the help of a diagram.

What is meant by a food web? Explain with the help of a simple diagram.

What are the regular and irregular reflection?Explain with the help of diagrams.

What is the cause of friction ? Explain with the help of labelled diagram.