d
(d)

When dipped in water

\(W_{\text {app }}=W_{\text {air }}-F_B\)

\(\Rightarrow 9 \,gm \times g=10 \,gm \times g-F_B\)

Where,

\(\left\{\begin{array}{l}V_c=\text { volume of cavity } \\ V_g=\text { volume of gold } \\ W_{\text {app }}=9 gm \\ W_{\text {air }}=10 gm \\ F_B=\text { force of buoyancy } \\ \rho_w=\text { density of water }=1 \\ \rho_g=\text { density of gold }=19.3\end{array}\right.\)

\(\Rightarrow 1 \times g=F_B\)

Now (total volume displaced) \(\times \rho_w \times g=1 \times g\)

\(\left(V_c+V_g\right) \times 1=1\)

\(V_c=1-\frac{\text { Mass of gold in air }}{\rho_g}=1-\frac{10}{19.3}=0.482 \,cc\)