A convex lens of foal length 30 cm and a concave lens of focal length 60 cm are placed in contact.If the object is placed 40 cm away from the combination ,, find the position of the image.

A convex lens of focal lenth 30 cm and a concave lens of focal length 60 cm are placed in contact.Find the power of the combination.

If a convex lens of focal length 80 cm and a concave lens of focal length 50 cm re combined together ,what will be their resulting power?

The size of the image of an object,which is at infinity, as formed by a convex lens of focal length 30 cm is 2 cm. If a concave lens of focal length 20 cm is placed between the convex lens and the image at a distance of 26 cm from the convex lens, calculate the new size of the image

Two lenses convex lens of focal length 30 cm in contact with a concave lens of focal length 20 cm, if they are placed 8.0 cm apart with their principal axes coincident. An object 1.5 cm in size is placed on the side of the convex lens. The distance between the object and the convex lens is 40 cm. Determine the magnification produced by the two-lens system, and the size of the image.

A compound lens is made of a convex lens of power 10 D and a concave lens of power 5 D. An object 2 cm high is placed in front of this combination at a distance 40 cm from it. Find nature and size of the image formed.

A compound lens is made of a convex lens of power 10 D and a concave lens of power 5 D. An object 2 cm high is placed in front of this combination at a distance 40 cm from it. Find nature and size of the image formed.

A compound microscope uses an objective lens of focal length 4 cm and eyepiece lens of focal length 10 cm. An object is placed at 6 cm from the objective lens. Calculate the magnifying power of the compound microscope. Also calculate the length of the microscope.