Electricity — Science STD 10 — Question

Explain why, a real image can be projected on a screen but a virtual image cannot.

An object is moved closer to an eye. What changes must take place in the eye in order to keep the image in sharp focus?

Draw ray diagrams showing the image formation by a concave mirror when an object is placed:

Between focus and centre of curvature of the mirror.

Explain clearly why, a person who has lost the sight of one eye is at a disadvantage compared with the normal person who has two good eyes.

Why do we see a rainbow in the sky only after rainfall?

Draw ray diagrams showing the image formation by a convex lens when an object is placed:
Between optical centre and focus of the lens.

The potential difference between the terminals of an electric iron is 240V and the current is 5.0A. What is the resistance of the electric iron?

Identify the device used as a spherical mirror or lens in following cases, when the image formed is virtual and erect in each case.

Object is placed between infinity and device, image formed is diminished and between focus and optical centre on the same side as that of the object.

A person having short-sight cannot see objects clearly beyond a distance of 1.5 m. What would be the nature and power of the corrective lens to restore proper vision?

Draw the magnetic lines of force due to a circular wire carrying current.