Which of the following ray diagrams is correct for the ray of light incident on a lens shown in the figure?

Name the type of lens that can be used as a magnifying glass. Give reason$(s)$ and draw a ray diagram to support your answer.

Which of the following conditions must be satisfied to obtain a magnified image of an object using a concave mirror?

The absolute refractive index of any medium is always $.....$

Name the type of mirror used in the following:
$(a)$ Solar furnace.
$(b)$ Side/rear-view mirror of a vehicle.
Draw a labelled ray diagram to show the formation of image in each of the above two cases.
Which of these mirrors could also form a magnified and virtual image of an object? Illustrate with the help of a ray diagram.

State the sign convention for lenses regarding object and image distances.