![What is meant by power of a lens? Write its SI unit. A student uses a lens of focal length 40 cm and another of - 20 cm. Write the nature and What is meant by power of a lens? Write its SI unit. A student uses a lens of focal length 40 cm and another of - 20 cm. Write the nature and](https://dwes9vv9u0550.cloudfront.net/images/2466609/e6f92879-8c11-4c90-9094-eab0e7276b22.jpg)
What is meant by power of a lens? Write its SI unit. A student uses a lens of focal length 40 cm and another of - 20 cm. Write the nature and
![Thin Lens Equation Examples & Problems | What is the Thin Lens Equation? - Video & Lesson Transcript | Study.com Thin Lens Equation Examples & Problems | What is the Thin Lens Equation? - Video & Lesson Transcript | Study.com](https://study.com/cimages/videopreview/thin_lens_equation-examples_and_questions-v01_thumbnbail_137631.jpg)
Thin Lens Equation Examples & Problems | What is the Thin Lens Equation? - Video & Lesson Transcript | Study.com
![Refraction through a lens. we have seen people using spectacles for reading. The watchmakers use a small glass to see tiny parts. Pistol or rifle shooters. - ppt download Refraction through a lens. we have seen people using spectacles for reading. The watchmakers use a small glass to see tiny parts. Pistol or rifle shooters. - ppt download](https://images.slideplayer.com/19/5873396/slides/slide_4.jpg)