What is the ratio of powers delivered by 20 V dc and 20 V peak ac to the same load resistance?

Explanation

`P=V^(2)//R`
`20 V` peak ac is equivalent to `20//sqrt(2) dc`
i.e., 14.14 V dc power
`("dc power")/("ac power")`
`=((20^(2)//R))/([(20//sqrt(2))^(2)//R])=(20^(2))/((20//sqrt(2))^(2))=2`