Question

A convex lens of focal length 15 cm is placed in front of a convex mirror. Both are coaxial and the lens is 5 cm from the apex of the mirror. When an object is placed on the axis at a distance of 20 cm from the lens, if is found that image coincides with the object is 40 cm. Consider only two steps. Calculate the radius of curvature of mirror

Solution

Correct option is

55 cm

 

Using,

                    

                

                         v1 = 60 cm

Now if R is radius of curvature of mirror then R + 5 = v1   

                          R = 55 cm.

SIMILAR QUESTIONS

Q1

 

A screen S is placed a distance b = 5 cm from a circular convex mirror as shown in figure. An object RP of height h = 3 cm is arranged a distance a = 5 cm from the screen. Where must an observer position himself to see the image of the entire object? What are the maximum dimensions of the object (with the given arrangement of the object, the mirror and the screen) for the mirror to reproduce and image of the entire object? The diameter of the mirror is d = 10cm.

                                                                            

 

                                                                     

Q2

A point object is placed at a distance of 30 cm from a convex mirror of focal length 30 cm. the image will form at                                                                                          

Q3

Figure shows two rays A and B being reflected by a mirror and going as A` and B`. The mirror

                                                                              

Q4

Figure shows three transparent media of refractive indices µ1, µ2 and µ3. A point object O is placed in the medium µ2. If the entire medium on the right of the spherical surface has refractive index µ1, the image forms at O`. If this entire medium has refractive index µ3, the image forms at O``. In the situation shown, 

                                                                                

Q5

An object of length 2.5 cm is placed at a distance of 1.5f from a concave mirror where f is the magnitude of the focal length of the mirror. The length of the object is perpendicular to the principal axis. Find the length of the image. Is the image erect or inverted?

                                                                                                   

Q6

A convex mirror has its radius of curvature 20 cm. Find the position of the image of an object placed at a distance of 12 cm from the mirror.

                                                                                            

Q7

which mirror should a boy use, if he stands straight in front of a mirror at a distance of 30cm away from it and sees his erect image whose height is 1/6 th of his real height, is

Q8

A hair dresser stands with her nose 20 cm in front of a plane mirror for what distance must she focus her eyes in order to see her nose in the mirror?

Q9

An object of height 5 cm is placed in midway between a concave mirror of radius of curvature 30 cm and a convex mirror of radius of curvature 30 cm. The mirrors are placed opposite to each other and are 60 cm apart. The position of the image formed by reflection at convex mirror is.

Q10

A point source of light S is placed on the major optical axis of concave mirror at a distance of 60 cm. At what distance from the concave mirror should a flat mirror be placed for the rays to converge again at the point S having been reflected from the concave mirror and then from the flat one? Will the position of the point where the rays meet change if they are first reflected from the flat mirror? The radius of the concave mirror is 80 cm.