Kučera studied physics at the Charles University in Prague and was the first scientist in Czech lands to examine the newly discovered effect of radioactivity. In 1912 he became professor of experimental physics at the university. He was the first to study droplets of mercury used as electrode (author of Zur Oberflächenspannung von polarisiertem Quecksilber, 1903). His work was the basis for the discovery of polarography by Jaroslav Heyrovský.
