What specific laws and acts of government in the 20th century were inspired by the concept of the “yellow peril? ”

There were many such laws, notably the Gentleman's agreement where Japan decided not to allow immigration into the US because the US didn't want Japanese people. There was also the immigration act of 1917 which prevented people from Asian countries from immigrating because they were not like Americans. The Cable act of 1922 also excluded people of asian origin because of the color of their skin.