You are given the following three lenses. Which two lenses will you use as an eye piece and as an objective to construct an astronomical telescope? Give reasons.

Which two main considerations arekept in mind while designing the objective of an astronomical telescope?

Which of the following lenses L_1 , L_2 and L_3 will you select as objective and eyepiece for constructing best possible (i) telescope and (ii) microscope? Give reason to support your answer.

You are given two convex lenses of short aperture having focal lengths 4 cm and 8 cm respectively.Which one of these will you use as an objective and which one as an eye piece for constructing a compound microscope?

You are given following current time graphs from two different sources: Name the type of current in two cases.

The astronomical telescope consists off objective and eye-piece.The focal length of the objective is

Suppose you are given a circle. Give a construction to find its centre.

For which of these would you use a histogram to show the data : The height of competitors in an athletics meet.Give reasons for each

Which of the following lenses would you prefer to use while reading small letters in a dicionary?

Name three metals that you come across in your dialy life and also give their uses.