Where should an object be placed in front of a convex lens to obtain a real and inverted image of the same size as the object?

$A$ plane mirror produces a magnification of

Zaheen uses a convex lens to make sunlight burn a hole in a piece of card. Zaheen changes the lens in the holder for another lens with twice the power. What will she have to do to focus the sunlight on the card?

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.

Draw ray diagrams showing the image formation by a convex mirror when an object is placed:
$(a)$ at infinity
$(b)$ at a finite distance from the mirror

Which of the following materials has maximum optical density?