 On the resignation of B Rama Rau he took over as the Governor.His tenure was the third-shortest (45 days) after B. N. Adarkar (42) and Amitav Ghosh (20).Compared to the latter two Governors Ambegaonkar's signature as RBI Governor does not appear on any Indian Rupee note, but his signature as Finance Secretary appeared on the second, third, and fourth Rupee one notes issued after independence.