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.
举一反三
- 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
- ignition coil
- coil tube with fins
- 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
- The voltage meter and current meter on the main switchboard shows ( <br/>). A: phase voltage and phase current of generator B: line voltage and line current of generator C: line voltage and line current of crane D: line voltage and line current of shore power