Sources of Energy — Science STD 10 — Question

The picture given here shows a person wearing 'half-moon' spectacles. What sort of eye-defect do do you think he has? Why are these particular spectacles useful to him?

A solution of a substance ‘X’ is used for white washing.

1. Name the substance ‘X’ and write its formula.
2. Write the reaction of the substance ‘X’ named in (i) above with water.

Write one reaction in which aluminium oxide behaves as a basic oxide and another in which it behaves as an acidic oxide.

List two properties of the images formed by convex mirrors. Draw ray diagram in support of your answer.

Give the functions of medulla.

What is the conventional direction of the flow of electric current? How does it differ from the direction of flow of electrons?

Describe with the help of a diagram, the nature, size and position of the image formed when an object is placed beyond the centre of curvature of a concave mirror.

Write some of the important uses of electromagnets.