Mirror- A mirror is things which mirrors light in a means such that the reflected light retains all or many of the an accurate or specific physical functions of the original light.

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Lenses- A lens is an optical device which concentrates a light beam or disperses it with refraction. A straightforward lens is composed only that a solitary piece of transparent glass, whereas a link lens is composed of multiple straightforward lenses (elements), commonly arranged follow me a common axis.

Mirrors are classified under 3 categories based on their geometry. In level mirrors, a parallel irradiate beam shifts its route in a plane mirror as a totality while continuing to be parallel. The images produced by a plane mirror space virtual photos of equal dimensions together that of original object.


Spherical mirrors have actually a curved reflecting surface, due to which parallel beam of light converge come or appear to diverge indigenous a allude called emphasis of the curved surface. Spherical winter are additional classified in 2 categories – concave and convex. In concave mirrors, parallel light beams kind a single convergent beam in a concave mirror, whose rays fulfill at the mirror's focus. In convex mirror, parallel beams space divergent in a convex mirror, with the rays showing up to diverge indigenous a particular intersection suggest "behind" the mirror. Parabolic mirrors emphasis the incoming parallel beams of irradiate to a particular, eal, tiny spot. Due to the fact that the irradiate rays space not parallel, parabolic reflectors space not ideal for imaging objects positioned nearby.

Mirror Formula:

1f=1u+1vfrac1f = frac1u + frac1vf1​=u1​+v1​

where, f= street of emphasis of the spherical mirror from the pole u = distance of thing measured indigenous the pole of the spherical mirror, and v = distance of image measured native pole the the spherical mirror.

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Similar come mirrors, lenses space classified follow to the curvature that the 2 optical surfaces:

· as soon as both surfaces space convex, lens is biconvex (double convex). As soon as both the surfaces have same curvature radius, climate the lens is dubbed an equiconvex lens.

· Biconcave (or also concave), is a lens with two concave surfaces.

· as soon as one of the surface is straight, depending on the curvature of the other surface the lens have the right to be a plano-convex or Plano-concave.

. Convex-concave or meniscus is a lens which has actually one convex face and one concave face. This type of lens is the one mostly used in corrective lenses.


Lens Formula:

1f=1v−1ufrac1f = frac1v - frac1uf1​=v1​−u1​

f = street of focus of the spherical lens indigenous the optical centre, u = distance of object measured indigenous the optical centre of the spherical lens, and also v = street of picture measured native the pole the the spherical lens.

Sign convention is a set of rules for setup image distance, thing distance, focal distance length, etc. Because that mathematical evaluation of photo forming. We have separate sign conventions because that spherical mirror and also lenses.

Sign Convention because that Spherical Mirrors:

· object is always placed come the leftwards of mirror.

· All ranges are approximated from winter pole.

· The ranges measured in the direction that the occurrence ray space positive and the distances measured in the direction opposite to that of the rays space negative.

· Positive room the distances measured follow me the y-axis over the main axis and negative are those measured follow me the y-axis listed below the key axis.


Sign Convention for Spherical Lenses:

· thing is constantly placed to the leftwards that lens.

· All distances are approximated from optical center of lens.

· Positive space the distances measured in the direction that the occurrence rays and negative are the ranges measured in the direction the contrary to that of the rays.

· Positive are the ranges measured follow me the y-axis above the key axis and an unfavorable are those measured along the y-axis listed below the main axis.

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· Convex lens has positive focal distance distance and concave lens has negative focal distance.