An object is placed in front of a thin convex lens of focal length 30 cm and a plane mirror is placed 15 cm behind the lens. If the final image of the object coincides with the object, the distance of the object from the lens is :
60 cm
30 cm
15 cm
25 cm
A
30 cm
B
60 cm
C
25 cm
D
15 cm
Open in App
Solution
Verified by Toppr
For autocallination by system, light should fall normally on plane mirror, since mirror is perpendicular to the principal axis. Hence the object must lie on secondary focus of the lens. From the Ray diagram u=30cm
Was this answer helpful?
10
Similar Questions
Q1
An object is placed in front of a thin convex lens of focal length 30 cm and a plane mirror is placed 15 cm behind the lens. If the final image of the object coincides with the object, the distance of the object from the lens is :
View Solution
Q2
An optical system consists of a thin convex lens of focal length 30 cm and a plane mirror 15 cm behind the lens. An object is placed 15 cm in front of the lens. The distance of the final image formed from the lens is
View Solution
Q3
A thin convex lens of focal length 30 cm placed in front of a plane mirror. An object is placed at a distance x from the lens (not in between lens and mirror) so that its final image coincides with itself. then, the value of x is
View Solution
Q4
A convex lens of focal length 15cm is placed in front of a plane mirror at a distance 25cm from the mirror. Where on the optical axis and from the centre of the lens should be small object be placed such that the final image coincides with the object?
View Solution
Q5
A convex lens of focal length 15 cm is placed on a plane mirror. An object is placed at 30 cm from the lens. The image will be