The focal lengths of the lenses are 20 and 40 cm, which one has the highest optical power?

The focal lengths of the lenses are 20 and 40 cm, which one has the highest optical power? a F = 20cm b F = 30cm c the optical powers of these lenses are the same

To solve the problem, you need to write down the following formulas:
1. D1 = 1 / F1;
2. D2 = 1 / F2;
Substitute the values into the formulas:
1. D1 = 1 / 0.2;
2. D2 = 1 / 0.3;
Let’s count:
1. D1 = 5;
2. D2 = 3;
Thus, it turns out that:
D1> D2, it follows that the desired lens with a focal length of 20 cm.
Answer: D1> D2, from this it follows that the desired lens with a focal length of 20 cm.