A: greater the current induced in the coil.
B: lower the current induced in the coil.
C: greater the resistance of the coil.
D: lower the resistance of the coil.
举一反三
- Fig 1 – 3 shows how it is that a coil of wire(导线圈)induces(感应) a current in another coil when the current in it is turned on or off.
- 5) Which one of the glowing magnetic field gives the largest magnitude? A: the field 2 cm away from a long, straight wire carrying a current of 3 A B: the field at the center of a flat, compact, circular coil, 2 cm in radius, with 10 turns, carrying a current of 0.3 A C: the field at the center of a solenoid 2 cm in radius and 200 cm long, with 1000 turns, carrying a current of 0.3A D: the field at the center of a long, straight, metal bar, 2 cm in radius, carrying a current of 300 A E: a field of 1 mT
- Semiconductor<br/>with a current is placed in a magnetic field perpendicular to the<br/>current and it induced electric field in the direction. This<br/>phenomenon is known as the ______ .
- ignition coil
- A circular loop of wire is held in a uniform magnetic field, with the plane of the loop perpendicular to the field lines. Which of the following will not cause a current to be induced in the loop? A: crushing the loop B: rotating the loop about an axis perpendicular to the field lines C: keeping the orientation of the loop fixed and moving it along the field lines D: pulling the loop out of the field
内容
- 0
coil tube with fins
- 1
The frequency of an alternator at a given r/min is determined by the _______ . A.number of turns of wire in the armature coil B.number of magnetic poles C.strength of the magnets used D.output voltage
- 2
导体切割磁场线，没有构成闭合回路的话，那么___The conductor cuts the magnetic field line without forming a closed loop, then___ A: 没有感应电流，没有电动势；no induced current, no electromotive force; B: 没有感应电流，有电动势；there is no induced current and there is an electromotive force; C: 有感应电流，没有电动势；there is an induced current and no electromotive force; D: 有感应电流，有电动势；there is an induced current and an electromotive force;
- 3
If the magnetic field B through<br/>a loop of wire is increasing, the<br/>induced magnetic field will be A: in<br/>the same direction as B B: in<br/>the opposite direction as B C: perpendicular<br/>to B D: at<br/>an acute angle to B E: there<br/>is no induced magnetic field
- 4
There exists an induced current flowing clockwise in the conducting loop shown in Figure. What is the direction of the magnetic field through the loop and how does the field vary in magnitude?[img=111x83]1803a3760763dd5.png[/img] A: Into the page and increasing. B: Into the page and decreasing. C: Into the page and steady. D: Out of the page and decreasing.