A thin equiconvex lens has focal length 10 cm and refractive index 1.5 . One of its faces is now silvered and for an object placed at a distance u in front of it, the image coincides with the object. The value of u is

A glass slab of thickness 2cm and refractive index 2 is placed in contact with a biconvex lens of focal length 20cm. The refractive index of the material of the lens 1.5 . The far side of the lens is silvered. Where should an object be placed in front of the slab so that it images on to itself?

A glass slab of thickness 2cm and refractive index 2 is placed in contact with a biconvex lens of focal length 20cm. The refractive index of the material of the lens 1.5 . The far side of the lens is silvered. Where should an object be placed in front of the slab so that it images on to itself?

A thin convex lens of focal length 30 cm is 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

A thin convex lens of focal length 30 cm is 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

A point object is placed at a distance of 12 cm from a convex lens of focal length 10 cm. On the other side of the lens, a convex mirror is placed at a distance of 10 cm from the lens such that the image formed by the combination coincides with the object itself. The focal length of the convex mirror is

A point object is placed at a distance of 12 cm on the axis of a convex lens of focal length 10 cm. On the other side of the lens, a convex mirror is placed at a distance of 10 cm from the lens such that the image formed by the combination coincides with the object itself. What is the focal length of convex mirror ?

A point object is placed at a distance of 12 cm from a convex lens of focal length 10 cm. On the other side of the lens, a convex mirror is placed at a distance of 10 cm from the lens such that the image formed by the combination coincides with the object itself. The focal length of the convex mirror is

Focal length of an equiconvex lens is 20 cm. The refractive index of material of the lens is 1.5. Now one of the curved surface is silvered. At what distance from the lens an object is to be placed, so that image coincides with the object ?