Two thin lens have a combined power of 10D in contact. When separated by 20 cm their equivalent power is `6.25D`. Find teir in dividual powers in dioptres-

Two thin lenses have a combined power of +9 D . When they are separated by a distance of 20 cm, their equivalent power becomes 27/5 D . Their individual powers (in diopters) are..............

Two thin lenses have a combined power of +9D.When they are separated by a distance of 20 cm, then their equivalent power becomes +27/5 D. Their individual powers (in dioptre) are

Two thin lenses have a combined power of +9D.When they are separated by a distance of 20 cm, then their equivalent power becomes +27/5 D. Their individual powers (in dioptre) are

Two thin lenses have a combined power of +9 D.When they are sparated by a distance of 20 cm. Their equivalent power becomes +(27)/(5)D .Their individual powers (in diopters)are

Two thin lenses of power +5 D and -2.5 D are in contact. What is the focal length of the combination ?

Two thin lenses of power +5 D and -2.5 D are in contact. What is the focal length of the combination ?

Two thin lenses of power +6 D and -2 D are in contact. What is the focal length of the combination ?

Two thin lenses of power + 6 D and - 2 D are in contact. What is the focal length of the combination ?