A concave mirror has a focal length of $25 \mathrm{cm}$. At which of the following distance should a person hold his face from this concave mirror so that it may act as a shaving mirror? Give reason for your choice.

An object is placed at the following distances from a concave mirror of focal length $15 \mathrm{cm}$, turn by turn. Which position of the object will produce a magnified real image?

An object is placed at the following distances from a concave mirror of focal length $15 \mathrm{cm}$, turn by turn. Which position of the object will produce a magnified virtual image?

An object is placed at the following distances from a concave mirror of focal length $15 \mathrm{cm}$, turn by turn. Which position of the object will produce a diminished real image? 

An object is placed at the following distances from a concave mirror of focal length $15 \mathrm{cm}$, turn by turn. Which position of the object will produce an image of same size as the object?

Which type of mirror has positive focal length?

(Choose from the following: Convex mirror/ Concave mirror)