The more rapidly a bar magnet (or other source of magnetic field) approaches a conducting wire loop, the
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.
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