9. Ray optics abd optical instruments Physics - 9. Ray optics abd optical instruments

A light ray enters through a right angled prism at point $P$ with the angle of incidence $30^{\circ}$ as shown in figure. It travels through the prism parallel to its base $B C$ and emerges along the face $A C$. The refractive index of the prism is:

• ✓
  $\frac{\sqrt{5}}{2}$
• B
  $\frac{\sqrt{3}}{4}$
• C
  $\frac{\sqrt{3}}{2}$
• D
  $\frac{\sqrt{5}}{4}$

Answer: A.

• ✓
  $28$
• B
  $17$
• C
  $32$
• D
  $34$

Answer: A.

• ✓
  $\sin ^{-1}\left(\frac{10 t_1}{t_2}\right)$
• B
  $\sin ^{-1}\left(\frac{t_2}{t_1}\right)$
• C
  $\sin ^{-1}\left(\frac{10 t_2}{t_1}\right)$
• D
  $\sin ^{-1}\left(\frac{t_1}{10 t_2}\right)$

Answer: A.

In the figure shown here, what is the equivalent focal length (in $cm$) of the combination of lenses (Assume that all layers are thin)?

• A
  $-50$
• B
  $40$
• C
  $-40$
• ✓
  $-100$

Answer: D.

• ✓
  Infinite
• B
  Zero
• C
  $f / 4$
• D
  $f / 2$

Answer: A.