Physics

Refraction at Spherical Surfaces and by Lenses

गोलाकार पृष्ठों और लेंसों द्वारा अपवर्तन

In Class 12 Physics, this topic from Chapter 9, Ray Optics and Optical Instruments, explains how light bends at curved spherical surfaces and passes through lenses. Students apply the Cartesian sign convention, derive and use the refraction formula for a spherical surface, and relate focal length, refractive index, and radii of curvature through the lens maker’s formula. They also study thin-lens formation, lens power, and combinations of lenses, using ray diagrams and numerical problems to connect image position, size, and nature with optical design.