Ray Optics Test...

The phenomena of total internal reflection is seen when angle of incidence is

A fish looking up through the water sees the outside world contained in a circular horizon. If the refractive index of water is 4/3and the fish is 12 cm below the surface, the radius of this circle in cm is

A point source of light is placed 4 m below the surface of water of refractive index 5/3. The minimum diameter of a disc which should be placed over the source on the surface of water to cut-off all light coming out of water is

Which of the following is not due to total internal reflection?

Light travels in two media A and B with speeds 1.8 × 10⁸ms^–1 and 2.4 × 10⁸ms^–1 respectively. Then, the critical angle between them is

The radius of curvature for a convex lens is 40 cm, for each surface. Its refractive index is 1.5. The focal length will be

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

A thin lens has focal length f₁ and its aperture has diameter d/2. It forms an image of intensity I. Now the central part of the aperture upto diameter d/2 is blockedby an opaque paper. The focal length and image intensity will change to

Four lenses are made from the same type of glass. The radius of curvature of each face is given below. Which will have the greatest positive power?

A convex lens of focal length 40 cm is in contact with a concave lens of focal length 25 cm. The power of combination is