Explain the difference between a plane mirror a cancave mirror and canvex mirror with respect the type and size of the inage prodyced
Answers
Answered by
5
I will explain briefly.
A plane mirror forms a virtual image always. It is formed behind the mirror. The image is formed at the same distance from the mirror as is the object from the mirror. The magnification is equal to 1. So size of the image is same as the size of the object.
The reason for this is that there is no curvature on the mirror. Its focal length is infinity. The rays from the object , perpendicular to mirror are always reflected perpendicularly. So all reflected rays are parallel. We can apply the explanation of spherical mirror with f = infinity.
For spherical mirrors:
1/v = 1/f - 1/u, u = negative as per convention.
2) For a convex mirror, f is positive. So v is positive.
So image is behind the mirror. Clearly the image is virtual.
magnification m = - v/u.
As v = uf / (u - f)
- v/u = f / (f - u)
Since f is positive and u is negative, m is always positive. So erect images are formed. Also f < (f-u), so image is diminished.
3) Concave mirror:
v = uf /(u - f)
u and f are negative. So it depends on u-f.
v is positive, if |u| < | f | or object is within focal length.
Then a virtual image is formed.
m = - v/u = f/(f-u) = + ve. So erect image is formed. The image is enlarged,
as |f-u| < |f|.
v is negative, if | u | > | f |. So in this case a real inverted image is formed.
m = -v/u = f/(f-u)
Magnification depends on the value f/(f-u). If |u| < 2 |f|, then an enlarged
real inverted image is formed. If |u| > 2 | f | then a diminished real
inverted image is formed.
A plane mirror forms a virtual image always. It is formed behind the mirror. The image is formed at the same distance from the mirror as is the object from the mirror. The magnification is equal to 1. So size of the image is same as the size of the object.
The reason for this is that there is no curvature on the mirror. Its focal length is infinity. The rays from the object , perpendicular to mirror are always reflected perpendicularly. So all reflected rays are parallel. We can apply the explanation of spherical mirror with f = infinity.
For spherical mirrors:
1/v = 1/f - 1/u, u = negative as per convention.
2) For a convex mirror, f is positive. So v is positive.
So image is behind the mirror. Clearly the image is virtual.
magnification m = - v/u.
As v = uf / (u - f)
- v/u = f / (f - u)
Since f is positive and u is negative, m is always positive. So erect images are formed. Also f < (f-u), so image is diminished.
3) Concave mirror:
v = uf /(u - f)
u and f are negative. So it depends on u-f.
v is positive, if |u| < | f | or object is within focal length.
Then a virtual image is formed.
m = - v/u = f/(f-u) = + ve. So erect image is formed. The image is enlarged,
as |f-u| < |f|.
v is negative, if | u | > | f |. So in this case a real inverted image is formed.
m = -v/u = f/(f-u)
Magnification depends on the value f/(f-u). If |u| < 2 |f|, then an enlarged
real inverted image is formed. If |u| > 2 | f | then a diminished real
inverted image is formed.
kvnmurty:
:-)
Answered by
8
Plane mirror is a type of mirror which forms image of of equal size to the object. It makes the left side of the object as right side in the image where as right side of the object as left side in the image. It always forms a virtual image which is always erect.
Concave mirror is a type of mirror which is is polished from the outer side of the sphere from which it is made up of . It always form the image of larger size then the object.
Convex mirror is a type of mirror which is is polished from the inner side of the sphere from which it is made up of . It always form the image of smaller size then the object.
Similar questions