A convergent lens of power 8 D is combined with a divergent lens of power `- 10 D`. Calculate focal length of the combination.

State the three laws of refraction of light. or A convergent lens of power 5 D is combined with a divergent lens of power -3D . What is the focal length of the combination?

a convex lens of power 3.5D is placed in contact with a concave lens of power -1.5D. Find the effective focal length of the combination.

A concave lens with power -7 D is coaxially placed adjacent to a convex lens with power + 12 D. Calculate the focal length of combined lens.

A converging lens of focal length 40 cm is kept in contact with a diverging lens of focal length 30 cm. Find the focal length of the combination.

A convex lens of power +5 D is placed in contact with a concave lens of power -4 D. What is the power of combination and nature of lens combination ?

Two lenses, one diverging of power 2 diopyre and the other converging of power 6 dioptre are combined together. Calculate focal length and power of the combination.

Two lenses, one diverging of power 2D and the other converging of power 6Darecombinedtogether.Calculate the focal lengthand power of the combination.