一个电阻为R，自感系数为L的线圈，将它接在一个电动势为<img src="https://nimg.ppkao.com/2019-04/wuacheng/2019043017104381196.jpg?sign=519c4b82ee56c228f7f805642e2eda92&t=62d74994" />的交变电源上，线圈的自感电动势为<img src="https://nimg.ppkao.com/2019-04/wuacheng/2019043017105088009.jpg?sign=7ef069e4992f97a6222d2c0691dcc624&t=62d74994" />则流过线圈的电流为（）<br /> <img src="https://nimg.ppkao.com/2019-04/wuacheng/201904301711045864.jpg?sign=ebe0ec1b013785ccaea8b9e8a1cbbb17&t=62d74994" />