Two gases A and B are filled at the same pressure in separate cylinders with movable pistons of radius \(\text{r}_\text{A}\) and \(\text{r}_\text{B}\), respectively. On supplyig an equal amount of heat to both the systems reversibly under constant presurre, the pistons of gas A nd B are displaced by 16 cm and 9 cm, respectively. If the change in their internal energy is the same, then the ration \(\displaystyle \frac{\text{r}_\text{A}}{\text{r}_\text{B}}\) is equal to