JEE Mains · Physics · STD 12 - 9. Ray optics and optical instruments
A person has been using spectacles of power- \(1.0\) diopter for distant vision and a separate reading glass of power \(2.0\) diopters. What is the least distance of distinct vision for this person \(.......cm\)
- A \(10\)
- B \(40\)
- C \(30\)
- D \(50\)
Answer & Solution
Correct Answer
(D) \(50\)
Step-by-step Solution
Detailed explanation
\(\frac{1}{ v }-\frac{1}{ u }=\frac{1}{ f }\) \(P =2 D =2 m ^{-1}\) \(\Rightarrow \frac{1}{ f }=\frac{2}{100} cm ^{-1}\) \(\frac{1}{ V }-\left(-\frac{1}{25}\right)=\frac{2}{100}\) \(\Rightarrow \frac{1}{ V }=\frac{1}{50}-\frac{1}{25}\) \(\Rightarrow V =-50\,cm\)
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