When a phase winding of a resolver carries alternating current, the amplitude of magnetic density at each point in the air-gap is produced by the winding changes in ______ distribution at certain instant.
举一反三
- A single phase ac induction motor has two windings, one is a run winding and the other is called a start winding. Strat winding can only work for a very short time to avoid overheated. A _____________ switch is installed inside motor to disconnect the strat winding when the motor speed reached 75% RPM.
- 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 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
- For 3-winding transformers, when we do the short circuit test, we can measure from winding 3, with winding 1 shorted and winding 2 open, then can get leakage impedance Z13 value. ( <br/>)
- 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