Two thin lenses of powers `2D` and `3D` are placed in contact. An object is placed at a distance of 30 cm from the combination The distance in cm of the image from the combination is

Two thin lenses of powers 2D and 4D are placed in close contact. An object is placed at a distance of 50 cm from the combination. What is the distance of the image from the combined lens ?

Lenses of power 3D and - 5D are combined to from a compound lens. An object is placed at a distance of 50 cm from this lens. Find the position of its image ?

Lenses of powers 3D and -5D are combined to from a compound lens. An object is placed at a distance of 50 cm from this lens. Calculate the position of its image

Two lenses of power 15D and -3D are placed in contact. The focal length of the combination is a

Two lenses of power 15D and -3D are placed in contact. The focal length of the combination is a

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