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AP EAMCET · PHYSICS · Ray Optics

If the far point of a short sighted person is 400 cm, then the power of the lens required to enable him to see very distant objects clearly is

  1. A \(-0.5 \mathrm{D}\)
  2. B \(+0.5 \mathrm{D}\)
  3. C \(+0.25 \mathrm{D}\)
  4. D \(-0.25 \mathrm{D}\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(-0.25 \mathrm{D}\)

Step-by-step Solution

Detailed explanation

\( v = -400 \text{ cm} = -4 \text{ m} \) \( P = \frac{1}{f} = \frac{1}{v} - \frac{1}{u} = \frac{1}{-4 \text{ m}} - \frac{1}{-\infty} \) \( P = -\frac{1}{4} \text{ D} = -0.25 \text{ D} \)