The curl equation [img=154x44]1803a2a153c85f5.png[/img]shows that : A: The time-varying magnetic field can generate an electric field, in which the elecric field lines is closed around the magnetic field line. B: The time-varying magnetic field can generate a magneitc field, in which the magnetic field lines is closed around the electric field line. C: The magnetic field lines is closed themselves. D: Flux continuity

The<br/>magnetic field lines are used to visually describe the distribution<br/>of the magnetic field around the magnet. For the following<br/>statement,( <br/>) is wrong. A: Each<br/>magnetic field line is a closed loop curve B: No<br/>two magnetic field lines can cross each other C: The<br/>length of the magnetic field line reflects the strength of the<br/>magnetic field D: The<br/>tangential direction of any point on any of the magnetic lines is the<br/>direction of the magnetic field at that point

In typical induction motors, the stator winding is connected to the source and the rotor winding is short-circuited for many applications, or may be closed through external resistances. Herein, we can also call “stator winding” and “rotor winding” the ( ) respectively. A: field winding and armature winding B: armature winding and field winding C: armature winding D: field winding

In the near future, driverless cars will be more focused on<br/>closed-field commercial vehicles.( )

In typical induction motors, the stator winding is connected to the source and the rotor winding is short-circuited for many applications, or may be closed through external resistances. Herein, we can also call “stator winding” and “rotor winding” the ( ) respectively. A: armature winding and field winding B: field winding and armature winding C: motor D: stationary

- Who closed the door? -Nobody. It( ) A: was closed by itself B: had closed itself C: was closed itself D: closed itself

The type of field generated by a DC tacho-generator is A: pulsating magnetic field B: static field C: rotating field D: do not need field

It was common practice then that when the store owners wantedto go on vacation theysimply . A: closed in B: closed on C: closed down D: closed up

You must keep your eyes （）. A: closed B: close C: be closed D: to closed

The noise of desks___could be heard out in the street. A: opened and closed B: to be opened and closed C: being opened and closed D: having been open and closed