Ray Optics and ...

We wish to make a plano convex lens of focal length 16 cm from glass having refractive index 1.5. It is to be used in air. What should be the radius of curvature of the curved surface?​

A convergent lens made of crown glass (refractive index 1.5) has focal length 20cm in air. If it is immersed in a liquid of refractive index 1.60, its focal length will be:​

If R₁ and R₂ are the radii of curvature of a double convex lens, which of the following will have the largest power?​

A concave lens of glass, refractive index 1.5, has both surfaces of same radius of curvature R. On immersion in a medium of refractive index 1.75, it will behave as a:​

If two thin lenses of focal length f₁ and f₂ are held in contact then the focal length of the combination will be 

A convex lens produces a real image m times the size of the object. What is the distance of the object from the lens?

What is the unit of power of lens?

A double convex thin lens made of glass of refractive index 1.6 has radii of curvature 15 cm each. The focal length of this lens when immersed in a fluid of refractive index 1.63 is​

1 dioptre =​

If two thin lenses of power p₁ and p₂ are held in contact then the power of the combination will be​