List of top Physics Questions on spherical lenses asked in BITSAT

Two plano-convex lenses (1 and 2) of glass of refractive index 1.5 have radii of curvature 25cm and 20cm. They are placed in contact with their curved surfaces towards each other and the space between them is filled with liquid of refractive index 4/3. The combination is:

A lens having focal length f and aperture of diameter d forms an image of intensity I. Aperture of diameter d/2 in the central region of lens is covered by a black paper. Focal length of lens and intensity of image now will be respectively:

A lens having focal length f and aperture of diameter d forms an image of intensity I. Aperture of diameter d/2 in central region of lens is covered by a black paper. Focal length of lens and intensity of image now will be respectively:

The given lens is broken into four parts and rearranged as shown. If the initial focal length is \( f \), then after rearrangement the equivalent focal length is â