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

An object of height $5 \, cm$ is placed perpendicular to the principal axis of a concave lens of focal length $10 \, cm$. If the distance of the object from the optical centre of the lens is $20 \, cm$,determine the position,nature,and size of the image formed using the lens formula.

The refractive indices of turpentine oil,kerosene,and alcohol are $1.47, 1.44$,and $1.36$ respectively. Based on this information,complete the following ray diagrams to show the path of a ray of light through each medium. (Give a reason for your answer.)

The size of an image of an object formed by a mirror with a focal length of $20\, cm$ is observed to be reduced to $1/3^{rd}$ of its size. At what distance is the object placed from the mirror? What is the nature of the image and the mirror?

$A$ convex mirror has a focal length $f$. $A$ real object is placed at a distance $f$ in front of it. The mirror produces an image at

The absolute refractive indices of water,glass,and diamond are $1.33$,$1.50$,and $2.42$ respectively. Which medium is the most optically dense?