part 16, light, reflection and refraction, chapter 9, science, class 10 (CBSE BOARD)

part 16, light, reflection and refraction, chapter 9, science, class 10 (CBSE BOARD)

6. Which of the following lenses would you prefer to use while reading small letters found in a dictionary? (a) A convex lens of focal length 50 cm. (b) A concave lens of focal length 50 cm. (c) A convex lens of focal length 5 cm. (d) A concave lens of focal length 5 cm.