State whether the following statement is true or false:
Spherical reflectors are used to obtain high temperatures in solar heating devices.

$A$ ray of light passing through the principal focus of a concave mirror,after reflection,travels in which direction?

How can you distinguish between a plane mirror,a convex mirror,and a concave mirror by merely looking at the image formed in each case?

An object is brought towards a concave mirror. How does the position and size of the image change?

We wish to obtain an erect image of an object,using a concave mirror of focal length $15\, cm$. What should be the range of distance of the object from the mirror? What is the nature of the image? Is the image larger or smaller than the object? Draw a ray diagram to show the image formation in this case.

Which type of an image is formed by a plane mirror?