What is Stopping Potential?

The stopping voltage (or stopping potential) refers to the voltage difference required to stop electrons from moving between plates and creating a current in the photoelectric experiment. ... The product of the charge on an electron and the stopping voltage gives us the maximum kinetic energy of that ejected electron.

c. barbarians with unexpected intelligence  

it is the background information on the characters and setting explained at the beginning of the story. the exposition will often have information about events that happened before the story began. the exposition is often the very first part of the plot.