题目1单选题
已知工频正弦电压有效值和初始值均为380V,则该电压的瞬时值表达式为( )A. <img src="https://tihai-oss-cloud.itihey.com/img/3d6d2daa754b320e5b4d23782e38c204.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/f88162870b198a5c069c07ada2e6bf8f.png">C. <img src="https://tihai-oss-cloud.itihey.com/img/5e691c73d8e4e8178882eeef8da42ce6.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/41fd9f00d36820de930baee192f00285.png">