Question

Оптическая сила линзы у очков равна 1,25дптр,2дптр и 5дптр.У какой линзы фокусное расстояние меньше?

Answer 1

Чем больше диоптрии, тем меньше фокусное расстояние

Ответ у 5дптр

Answer 2

Optical Power of Lenses in Eyeglasses

The optical power of a lens is a measure of its ability to bend light. It is typically measured in units called diopters (Dptr). The higher the diopter value, the stronger the lens and the greater its ability to bend light.

In the given question, we are provided with three lenses with optical powers of 1.25 Dptr, 2 Dptr, and 5 Dptr. We need to determine which lens has a shorter focal length.

Relationship between Optical Power and Focal Length

The focal length of a lens is the distance from the lens at which parallel rays of light converge or diverge after passing through the lens. It is inversely proportional to the optical power of the lens.

The formula to calculate the focal length of a lens is:

Focal Length (in meters) = 1 / Optical Power (in diopters)

Calculating the Focal Lengths

Let's calculate the focal lengths of the three lenses provided:

1. Lens with an optical power of 1.25 Dptr: - Focal Length = 1 / 1.25 = 0.8 meters

2. Lens with an optical power of 2 Dptr: - Focal Length = 1 / 2 = 0.5 meters

3. Lens with an optical power of 5 Dptr: - Focal Length = 1 / 5 = 0.2 meters

Comparison of Focal Lengths

From the calculations above, we can see that the lens with an optical power of 5 Dptr has the shortest focal length of 0.2 meters. This means that this lens has the strongest bending power and will converge or diverge light at a shorter distance compared to the other lenses.

Therefore, among the lenses with optical powers of 1.25 Dptr, 2 Dptr, and 5 Dptr, the lens with an optical power of 5 Dptr has the shortest focal length.

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