Where should an object should be placed so that a real and inverted image of same size is obtained by a convex lens?
Object should be place at 2f or centre of curvature C1 of convex lens, to get image of given property. Convex lens is also called converging lens. Parallel rays of light, passing through convex lens join or converge at a one point.
At what distance the object must be placed before a concave mirror so that the image will be same size of the object?
▶▶So, the object must be placed between Centre of Curvature and Focus at the distance of 30 cm from the mirror.
At what distance should an object be placed in front of a concave mirror of focal length 15 cm to get an image of the same size?
For a concave mirror, image size is same as the object size when it is placed at the center of curvature. Since radius of the mirror is twice the focal length, center of curvature lies at a distance of 30 cm from the pole. Hence, an object kept at 30 cm will produce an image of the same size as that of the object.
What are convex lenses in?
A convex lens is a converging lens. When parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus. The distance between the principal focus and the centre of the lens is called the focal length.
Is convex lens negative?
According to Cartesian sign convention, object distances (u) are always negative as the object is placed to the left of the mirror/lens. Focal length (f) is positive for a convex lens and convex mirror. Focal length is negative for concave lens and concave mirror.
Is V positive in convex lens?
And for image distance, V in lens it is taken as positive in Convex lens since image is formed on +X side. It is taken as negative in Concave lens since image is formed in -X side of the Cartesian. In Concave mirror V is taken as positive and negative for convex mirror.
Is concave lens positive or negative?
| focal length | object distance | |
|---|---|---|
| concave mirror | positive | positive |
| convex mirror | negative | positive |
| converging lens | positive | positive |
| diverging lens | negative | positive |
Why is a convex mirror negative?
Since, object is always placed in front of the mirror hence the sign of object is taken as negative. In the case of convex mirror, image always formed behind the mirror, thus the distance of image is taken as positive.