WBCS.LIVE practice question

The power of a lens is +2.0D. The focal length of the lens and its nature are

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. 50 cm, concave
  2. 50 cm, convex
  3. 100 cm, convex
  4. 100 cm, concave

Correct answer and explanation

Correct answer: 50 cm, convex

Explanation: āœ… Correct Answer: B. 50 cm, convex šŸ“š Explanation: The focal length (f) is calculated as 1 divided by the power (P). For a power of +2.0D, the focal length is 1/2 meters, which equals exactly 50 centimeters. A positive power value indicates that the lens is 'convex' or converging in nature. These lenses are commonly used to correct long-sightedness (hypermetropia).