A convex lens of focal length $$f$$ is placed somewhere in between an object and a screen. The distance between the object and the screen is $$x$$. If the numerical value of the magnification produced by the lens is $$m$$, then the focal length of the lens is

Focal length of a convex lens will be maximum for

Consider a glass slab which is silvered at one side and the other side is transparent. Given the refractive index of the glass slab to be 1.5. If a ray of light is incident at an angle of $$45^{\circ}$$ on the transparent side, then the deviation of the ray of light from its initial path, when it comes out of the slab is

In refraction, light waves are bent on passing from one medium to second medium because, in the second medium