What kind of mirrors are used in shopping centres to watch the activities of the customers?

What type of mirror could be used:

(a) as a shaving mirror?

(b) as a shop security mirror?

Which type of mirror is usually used as a rear-view mirror in motor cars ?

A ray of light going towards the of a convex mirror becomes parallel to the principal axis after reflection from the mirror. Draw a labelled diagram to represent this situation.

Fill in the following blank with a suitable word:

A ray of light which is parallel to the' principal axis of a _______, appears to be coming from focus after reflection from the mirror.