A thin concave lens in the illustration has a focal length o

A thin concave lens in the illustration has a focal length of f. An object, represented by the arrow, is positioned at a distance of 1.5f from the center of the Ictus. Where will the image form? At a distance of 3f to the right of the lens. At a distance of 3f to the left of the lens. At a distance of 3f =5 to the right of the lens. At a distance of 3f =0 to the left of the lens. The image in a plane mirror of a person standing at a distance d in front of the mirror appears to the person to be: upright, real, and a distance d away from the person upright, virtual, and a distance 2d away from the person vertically inverted, virtual, and a distance 2d away from the person vertically inverted, real, and a distance d away from the person A lighted candle is placed a short distance from a plane mirror, as shown. At which location will the image of the flame appear to be located? A fiber optic cable is made of clear plastic with an index of refraction of n = 1:50. For what range of angles of incidence with the lateral surface of the fiber, will light totally reflect and remain inside the plastic fiber?

Solution

Focal length f = f

Distance of the object u = -(1/5) f

From the relation (1/u)+(1/v) = (1/f)

                          (5/f) +(1/v) = (1/f)

                                   (1/v) =(1/f)-(5/f)

                                          =(1-5)/f

                                          = -4/f

From this image distance v = -f/ 4

Answer is option(D ).

Since the concave lens forms an image is always formed inside the focal length of the lens and it is formed in the same side of the object.

(16).The image is upright ,virtual and a distance 2d away from the person.