- what is motional emf?
- explain magnetic braking device?
The electric field in the metal bar causes a potential difference of V = El = vBl. If the bar slides along metal rails, a closed circuit is set up with current flowing in the counterclockwise direction, up the bar and then around the metal rail back to the bottom of the bar. This is called an induced current. The moving bar is a source of an electromotive force, called motional emf, since the emf is generated by the motion of the bar.The force is defined as:
The magnitude of the induced emf can be increased by increasing the strength of the magnetic field, moving the bar faster, or using a longer bar.
The magnetic brake system based on the principle of electromagnetism. When dc/ac current passes through the stator or field winding the iron core in the stator winding get magnetized. Magnetic flux is produced between the south & north pole of stator winding. Armature winding is provided on the slotted shaft & shaft is placed between stator winding. Armature winding does not carry current.
When dc/ac current passes through the stator winding powerful magnetic flux are produced & it opposes the rotary motion of shaft. Due to the magnetic locking between stator winding & armature braking effect is obtained.
The magnetic brake system based on the principle of electromagnetism. When dc/ac current passes through the stator or field winding the iron core in the stator winding get magnetized. Magnetic flux is produced between the south & north pole of stator winding. Armature winding is provided on the slotted shaft & shaft is placed between stator winding. Armature winding does not carry current.
When dc/ac current passes through the stator winding powerful magnetic flux are produced & it opposes the rotary motion of shaft. Due to the magnetic locking between stator winding & armature braking effect is obtained.