A vessel of depth ‘\( d \)’ is half filled with oil of refractive index \( n_{1} \) and the other half is filled with water of refractive index \( n_{2} \). The apparent depth of this vessel when viewed from above will be:
\( \dfrac{d n_{1} n_{2}}{2(n_{1}+n_{2})} \)
\( \dfrac{d n_{1} n_{2}}{(n_{1}+n_{2})} \)
\( \dfrac{d(n_{1}+n_{2})}{2 n_{1} n_{2}} \)
\( \dfrac{2 d (n_{1}+n_{2})}{n_{1} n_{2}} \)