The Human Eyes And The Colourful World — Science STD 10 — Question

It is desired to obtain an erect image of an object, using concave mirror of focal length of 12cm.
What should be the range of distance of a object placed in front of the mirror?

A portable radio has a built-in transformer so that it can work from the mains instead of batteries. Is this a set-up or step down transformer?

Which particles constitute the electric current in a metallic conductor?

What type of lens is used to correct:

1. Hypermetropia?
2. Myopia?

Which defect of vision can be rectified:
By using a concave lens?

What is the far point and near point of the human eye with normal vision?

List, in order, the parts of the eye through which light passes to reach the retina.

What is the name of the phenomenon in which the right side of an object appears to be the left side of the image in a plane mirror?

A resistance of 20 ohms has a current of 2 amperes flowing in it. What potential difference is there between its ends?

Define:

radius of curvature.