If a prism can displace an image one centimeter at a distance of one meter, what is its power?

• A. 1 prism diopter
• B. 2 prism diopters
• C. 3 prism diopters
• D. 0.5 prism diopters

Answer: (A)

To determine the power of a prism in prism diopters, the formula used is that the power in prism diopters is equal to the displacement of the image (in centimeters) divided by the distance from the prism (in meters).

In this scenario, the prism displaces an image by one centimeter at a distance of one meter. Utilizing the formula:

Power (in prism diopters) = Displacement (in cm) / Distance (in m).

Substituting the given values:

Power = 1 cm / 1 m = 1 prism diopter.

This calculation directly leads to the conclusion that the power of the prism is indeed 1 prism diopter. Therefore, this answer is correct as it accurately reflects the relationship between the displacement of light and the distance of observation, aligning perfectly with the definition of prism power.