Uses of concave mirror:
When a concave mirror is held near the face such that the face is between the pole and the focus of the concave mirror, the mirror forms an upright and magnified image. So even the tiny hairs on the facecan easily be seen. For this a concave mirror of large focal length ( so that the face always lie between its focus and the pole) and large aperture ( so as to view the entire face) is used.
If a parallel beam of light is incident on a concave mirror, it is focuses the beam of light to a point. This fact enables us to use it as a doctor's head mirror to concentrate the beam of light on a small area of the body part to be examinedsuch as teeth, nose, throat and ear etc.
For this a parallel beam of light is made to fall on the concave mirror attached to the band tied at the fore head of doctor examining the body part.
In torch light, search light and head lights of the vehicles a concave highly polished metallic surface is used as a reflector to obtain a parallel beam of light to focus at the longer distance.
For this, the source of light (i.e., bulb) is placed at the focus of the concave reflector ( mirror). The rays of light incident on the concave reflector from the bulb after reflection from a parallel beam.
Uses of Convex Mirror
A convex polished metallic surface is used in street lamp as a reflector so as to diverge light over a larger area.
Rear View Mirror
Convex mirrors are used as rear view mirrors in vehicles.
A driver prefers to use a convex mirror as a rear view mirror because of the following two reasons
A convex mirror always produces an erect image of the objects.
The images formed in a convex mirror is highly diminished or much smaller than the objec, due to which a convex mirror gives a wide field of view of the traffic behind.
Shop Security Mirrors
By placing a big convex mirror at a strategic point in the shop, the shop owner or the manager can keep an eye on the customers to look for thieves and shop lifters among them.
Uses of Convex Lenses
- Convex lenses are used in spectacles to correct the defffective vision called hepermetropia or longsightedness.
Convex lens is used for making a simple camera.
Convex lens is used as a magnifying glass (or magnifying lens)(by palmists, watchmakers, etc.).
Convex lens is used in making microscopes, telescopes and slide projectors (or film projectors).
Uses of Concave Lenses
- Concave lenses are used in spectacles to correct the defect of vision called myopia (or shortssightedness).
Concave lens is used as eye-lens in Galilean telescope.
Concave lenses are used in combination with convex lenses to make high quality lens systems for optical instruments.
Concave lens is used in wide-angle spyhole in doors.