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what is the power of a 32.5-cm-focal-length lens? what is the focal length of a –6.75-d lens? are these lenses converging or diverging?

User Lissett
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1 Answer

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Final answer:

The power of a 32.5-cm-focal-length lens is 3.08 diopters, making it a converging lens, while the focal length of a –6.75-diopter lens is -14.8 cm, indicating it is a diverging lens.

Step-by-step explanation:

To find the power of a 32.5-cm-focal-length lens, we use the formula power (P) in diopters (D) which is given by P = 1/f, where f is the focal length in meters. For the first part of the problem:


  • Convert focal length from cm to meters: 32.5 cm = 0.325 m

  • Calculate power: P = 1/f = 1/0.325 m = 3.08 D

For a lens with a power of 3.08 D, it is a converging lens because it has a positive power value.

For the second part:


  • A lens with a power of –6.75 D is a diverging lens, indicated by the negative sign.

  • Convert power to focal length: f = 1/P => f = 1/–6.75 D = -0.148 m or -14.8 cm

In summary, the power of the 32.5-cm-focal-length lens is 3.08 D and is a converging lens, while the focal length of a –6.75-d lens is -14.8 cm and is a diverging lens.

User Bungdito
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