The phenomenon of superconductivity was discovered by Kammerlingh Onnes in*1 point1931191119211811

The phenomenon of superconductivity was discovered by Heike Kamerlingh Onnes in 1911. This discovery occurred when he cooled mercury to a temperature of 4.2 K (approximately -268.95 °C) and observed that its electrical resistance disappeared entirely. This remarkable occurrence suggested that electrons could move through the material without any energy loss, leading to what we now know as superconductivity. The significance of this discovery extends beyond just the realm of physics; it has paved the way for numerous technological advancements, including the development of powerful magnets and improved electronic devices. Furthermore, superconductivity has practical applications in fields such as MRI machines, particle accelerators, and lossless power transmission. Hence, the correct answer to your question is 1911.