R =10Ω, C= 10mF, L=50mH. According to Baidu question bank, the underdamping formula of second-order circuit is r =10Ω, C= 10mF, L=50mH. Formula refers to a general format, which is expressed by mathematical symbols. The formula of a certain relationship between various quantities (such as laws or theorems) can generally be applied to the ways and means of similar things.