Two lenses of power`+2.50D`and`-3.75D`are combined to form a compound lens Its focal length in cm,will be

Two lenses of power 6 D and – 2 D are combined to form a single lens. The focal length of this lens will be

Two lenses of power 6 D and – 2 D are combined to form a single lens. The focal length of this lens will be

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 +12 D and -2 D are combined together. What is their equivalent focal length ?

Two lenses of power + 12D and - 2D are combined together. What is their equivalent focal length?

Two lenses of power +12 D and -2D are combined together.What is their equivalent focal length?

Power of a lens is -5d, its focal length is: