List of top Physics Questions on Ray optics and optical instruments asked in AP ECET

An endoscope is employed by a physician to view the internal parts of a body organ. It is based on the principle of

An endoscope is employed by a physician to view the internal parts of a body organ. It is based on the principle of

A convex lens has its radii of curvature equal. The focal length of the lens is $f$. If it is divided vertically into two identical plano-convex lenses by cutting it, then the focal length of the plano-convex lens is $(\mu=$ the refractive index of the material of the lens $)$

A thin converging lens of focal length $ f = 25\, cm $ forms the image of an object on a screen placed at a distance of $ 75\, cm $ from the lens. The screen is moved closer to the lens by a distance of $ 25\, cm $ . The distance through which the object has to be shifted, so that its image on the screen in sharp again is