题目10单选题
已知一个2Ω的电阻,通过电阻的电流是:<img src="https://tihai-oss-cloud.itihey.com/img/2fcda0650ae75b15eab90992b90d9762.webp">A,求电阻上电压的有效值A. 20VB. <img src="https://tihai-oss-cloud.itihey.com/img/1f89b2a2a1fc98e62567d6bbe5584035.webp"> VC. <img src="https://tihai-oss-cloud.itihey.com/img/9c7f901a9f589de9e51c2d2af9d7c588.webp">V