一个500匝的线圈，其电阻为5Ω，将它与电阻为495Ω的电热器连成闭合电路．若在0.3s内，穿过线圈的磁通量从0.03Wb均匀增加到0.09wb，则线圈中产生的感应电动势为______V，通过电热器的电流为______A．
根据法拉第电磁感应定律得，E=n
=500×△Φ △t
V=100V．0.09-0.03 0.3
根据闭合电路欧姆定律得，I=
=E R+r
A=0.2A．100 495+5
故答案为：100，0.2．
| 从对话后的方框中选择适当的选项补全对话。 | |
| M: I hear there's going to be a basketball match this Sunday. Tom and I are going to watch it. 1______ W: Of course. Basketball is my favorite, but I have no ticket to the match. What a pity! M: You're lucky. I have some free tickets. 2______ W: Great! 3______ M: Let's meet at the bus stop at half past five. W: I think there must be a big crowd of people there at that time. 4______ M: OK. See you at five o'clock. W: See you.
| |