A microscope M is focused on an object P . A glass slab having a...

When a glass slab of thickness $t$ and refractive index $\mu$ is inserted between an object and a microscope, the apparent shift of the object is given by:

\Delta x = t \left(1 - \dfrac{1}{\mu}\right)<br><br>Givent = 2.1 $\text{ cm} and$\mu = 1.5 = $\dfrac{3}{2}, substituting these values into the formula gives:<br><br>\Delta$x = 2.1 \left(1 - \dfrac{2}{3}\right)$<br><br>$\Delta x = 2.1 \times \dfrac{1}{3}$<br><br>$\Delta x = 0.7 \text{ cm}$<br><br>The object appears to be shifted closer by$0.7 \text{ cm}$. Therefore, the microscope must be shifted by$0.7 \text{ cm}$to bring the object back into focus.$