如图所示，矩形线圈有N匝，长为a，宽为b，每匝线圈电阻为R，从磁_爱下问搜题

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问题选择题

如图所示，矩形线圈有N匝，长为a，宽为b，每匝线圈电阻为R，从磁感应强度为B的匀强磁场中以速度v匀速拉出来，那么，产生的感应电动势和流经线圈中的感应电流的大小应为（　　）

A．E=Bav，

B．E=NBav，

C．E=Bav，

D．E=NBav，

答案

答案：D

选择题

某溶液中存在五种离子：NO₃^－、SO₄²^－、Fe³⁺、H⁺和R离子，其物质的量之比为2:3:1:3:1，则R可能为（）

A．Fe²⁺

B．Mg²⁺

C．C1^－

D．Ba²⁺

补全对话，情景问答

A. It may be a big kite.

B. It can't be a bird.

C．It is a kite.

D. And he is the only child who likes flying kites.

Mary: Tom, look! What's that on the tree?
Tom: Oh,it looks like a bird.
Mary:    1   You know no bird is so big and colourful.   2
Tom: Er... Why not go and have a look?
Mary:    3
Tom: You're right Mary.   4    How beautiful it is!
Mary: Yes. Whoes kite is it, do you think?
Tom: It may be Jim's. He told l11e his kite flew a way this morning.
Mary:    5
Tom: Oh. Let's go and bring it back to him.
Mary: I agree. He-must be very happy.

1. _____ 2. _____ 3. _____ 4. _____ 5. _____