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物理 MC choice
1. The rated values of both bulbs are " 12 W , 6 V " . The two bulbs are operating at their rated values. If the reading of the ammeter is 125 mA , fing the efficiency of the transformer .
A. 40 %
B. 60 %
C. 80 %
D. 100 %
2. A rigid rectangular conducting loop PQRS is connected to a cell as shown. It is held at rest horizontally within a uniform magnetic field which is parallel to the plane of the loop and perpendicular to its side RS.
Which of the following statements is / are correct ?
(1) The side RS of the loop experiences an upward magnetic force.
(2) The loop experiences a torque due to the magnetic field.
(3) The magnetic flux linking the loop due to the uniform magnetic field is zero .
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
3. PQ and RS are two parallel metal rails with separation L. A metal rod XY resting on the rails moves with velocity v perpendicular to its length across a uniform magnetic field of flux density B pointing into the paper as shown. If the rod makes an angle θ with the rails , what is the potential
difference across Q and S ? ( Assume that the rod is always in contact with the rails.)
3 個解答
- 匿名8 年前最愛解答
1.請補充第一題的問題，請問是連接多少V的電源呢?
2.請問圖像在那裏?
2013-01-26 02:55:01 補充：
這樣很難了解當中的細節
2013-01-28 00:53:50 補充：
請問能用相機拍攝嗎?
- 天同Lv 78 年前
You could provide the information given in the diagrams in words. For example, in Q1, how are the bulbs connected? Does the meter measure the secondary (or primary current)? What is the turn-ratio of the transformer...etc
2013-01-26 11:00:48 補充：
You could provide the information given in the diagrams in words. For example, in Q1, how are the bulbs connected? Does the meter measure the secondary (or primary current)? What is the turn-ratio of the transformer...etc
- 8 年前
hontung ,
我沒有 scarner , sorry !!!!
2013-01-27 21:41:22 補充：
Hontung ,
okay , i know !!!!
2013-01-27 23:03:00 補充：
天同 ,
thankyou your idea !!!!
thankyou !!!!
2013-01-29 14:00:55 補充：
Houtung ,
I hope i can put the photo with yahoo knowledge la ... ...
