A printed page is kept pressed by a glass cube (\( \mu = 1.5 \)) of 5 cm edge. By what amount will the printed letters appear to be shifted when viewed from the top?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 1.7 cm
Seen from directly above through a block of thickness \( t \) and refractive index \( \mu \), an object under it appears raised by the apparent shift \( t\,(1 - 1/\mu) \).
\( \displaystyle \text{shift} = t\left(1 - \frac{1}{\mu}\right) = 5\left(1 - \frac{1}{1.5}\right) = 5 \times \frac{1}{3} \)
\( \displaystyle \text{shift} = 1.67\,\mathrm{cm} \approx 1.7\,\mathrm{cm} \)