WBJEE · Physics · Ray Optics
The human eye has an approximate angular resolution of \(\theta=5.8 \times 10^{-4} \mathrm{rad}\) and typical photo printer prints a minimum of 300 dip (dots per inch, 1 inch \(=2.54 \mathrm{~cm}\) ). At what minimal distance \(d\) should a printed page be held so that one does not see the individual dots?
- A \(20.32 \mathrm{~cm}\)
- B \(29.50 \mathrm{~cm}\)
- C \(14.59 \mathrm{~cm}\)
- D \(6.85 \mathrm{~cm}\)
Answer & Solution
Correct Answer
(C) \(14.59 \mathrm{~cm}\)
Step-by-step Solution
Detailed explanation
\(\theta=\frac{x}{d}\) \(5.8 \times 10^{-4}=\frac{2.54}{300} \times \frac{1}{d}\) \(d=14.59 \mathrm{~cm}\)
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