After refraction through a concave lens, a ray of light emerges parallel to the principal axis. Under what condition does it happen? - Quora
![A convex lens A of focal length 20 cm and a concave lens B of focal length 5 cm are kept along the same axis with the distance d between them. If A convex lens A of focal length 20 cm and a concave lens B of focal length 5 cm are kept along the same axis with the distance d between them. If](https://gs-post-images.grdp.co/2022/8/a-convex-lens-a-of-focal-length-20-cm-and-a-concave-lens-b-img1661409979057-91.png-rs-high-webp.png)
A convex lens A of focal length 20 cm and a concave lens B of focal length 5 cm are kept along the same axis with the distance d between them. If
![A convex lens A of focal length 20cm and a concave lens G of focal length 5cm are kept along the same axis with the distance between them. If a parallel beam A convex lens A of focal length 20cm and a concave lens G of focal length 5cm are kept along the same axis with the distance between them. If a parallel beam](https://www.vedantu.com/question-sets/5f16a0a5-95d2-4cb5-b754-7a6788995bd93435487036600868184.png)