Question

An object is 30.0 cm from a spherical mirror, along the central axis. The absolute value of lateral magnification is 1/2. The image produced is inverted. What is the focal length of the mirror?

Solution

Correct option is

f = –10 cm

 

Only concave mirror can form inverted image therefore

              u = –30 cm,   

                

           

              f = –10 cm.

SIMILAR QUESTIONS

Q1

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?

                                                                                                   

Q2

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.

                                                                                            

Q3

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

Q4

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?

Q5

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.

Q6

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

Q7

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.

Q8

A small object is placed on the principal axis of  a concave spherical mirror of radius 20 cm at a distance of 30 cm. By how much will the position and size of the image alter, when a parallel – sided slab of glass of thickness 6 cm and refractive index 1.5 is introduced between the centre of curvature and the object? The parallel sides are perpendicular to the principal axis

Q9

 

A concave mirror has a radius of curvature of 24 cm How far is an object from the mirror if an image is formed that is  

(a) virtual and 3.0 times the size of the object     

(b) real and 3.0 times the size of the object and

(c) real and 1/3 the size of the object?