NCERT Question 6 (MCQ) - Chapter 10 Class 10 - Light - Reflection and Refraction

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.

Answer

Answer is (c) A convex lens of focal length 5 cm.

Explanation 

A concave lens will always give a diminished image.

So, we use a convex lens as it makes an enlarged image

Now, the smaller the focal length, the greater will be the power of the lens.

Hence, a convex lens of focal length 5cm will be preferable.