1. Given data

   • Resistance of galvanometer: $R_g = 72\,\Omega$
   • Shunt resistance: $R_s = 8\,\Omega$

2. Current division principle Since the galvanometer and shunt are connected in parallel, the same potential difference acts across both.

   Let:

   • Current through galvanometer = $I_g$
   • Current through shunt = $I_s$

   Then, $I_g R_g = I_s R_s$

   Substituting values: $I_g \cdot 72 = I_s \cdot 8$

   $\frac{I_g}{I_s} = \frac{8}{72} = \frac{1}{9}$

3. Find total current Total current is: $I = I_g + I_s$

   Since $I_g : I_s = 1:9$, we get $I = 1 + 9 = 10 \text{ parts}$

   So the fraction through galvanometer is: $\frac{I_g}{I} = \frac{1}{10}$

4. Convert into percentage $\frac{1}{10} \times 100 = 10\%$

5. Option check

   • A: $0.1\%$ ❌
   • B: $10\%$ ✅
   • C: $25\%$ ❌
   • D: $0.25\%$ ❌

Therefore, the percentage of total current passing through the galvanometer is $10\%$.