Who Performs Work in EMF Generation with Changing Magnetic Fields?

Click For Summary
SUMMARY

Electromotive force (EMF) is generated by moving a closed loop of wire through a constant magnetic field, with the work being performed by the individual pushing or rotating the coil. Additionally, EMF can indeed be generated through a non-constant magnetic field, as changing magnetic flux induces EMF without the need for physical rotation of the coil. This principle is fundamental to the operation of large generators and alternators, where a magnet is rotated on a shaft within fixed coils.

PREREQUISITES
  • Understanding of electromagnetic induction principles
  • Familiarity with Faraday's Law of Electromagnetic Induction
  • Knowledge of generator and alternator mechanics
  • Basic concepts of magnetic fields and flux
NEXT STEPS
  • Study Faraday's Law of Electromagnetic Induction in detail
  • Explore the mechanics of generators and alternators
  • Learn about the relationship between magnetic flux and induced EMF
  • Investigate applications of EMF in various electrical engineering contexts
USEFUL FOR

Students and professionals in electrical engineering, physics enthusiasts, and anyone interested in the principles of electromagnetism and energy generation.

fricke
Messages
38
Reaction score
3
I understand that EMF is generated by moving a closed loop of wire through a constant magnetic field. I am confused about one thing, who is actually doing work here? (of course it is not magnetic field).
 
Physics news on Phys.org
and one more question. Can EMF be generated through non-constant magnetic field? say, the magnetic field is changing with time.
 
Question 1: You are doing the work by pushing or rotating the coil.
Q2: Yes. If the magnetic field is changing with time, you don't have to rotate the coil. The changing magnetic flux induces an emf.
 
fricke said:
and one more question. Can EMF be generated through non-constant magnetic field? say, the magnetic field is changing with time.

yes, that's the way most large generators/alternators work. The magnet is rotated on a shaft inside the surrounding fixed coils

Dave
 

Similar threads

Graduate Motional EMF in the frame of a moving wire
  • · Replies 28 ·
Replies
28
Views
2K
Undergrad Motional EMF for loops of wire vs conducting plates
  • · Replies 9 ·
Replies
9
Views
2K
Undergrad Motional EMF in Faraday disc, co-rotating magnet axial mean flux
  • · Replies 5 ·
Replies
5
Views
643
A Question About Induction: Faraday's Law versus Motional EMF
  • · Replies 17 ·
Replies
17
Views
2K
Undergrad Why is the negative sign in the equation for motional EMF often discarded?
  • · Replies 7 ·
Replies
7
Views
4K
Graduate How is there not an infinite regress in the EMF of a motor?
  • · Replies 8 ·
Replies
8
Views
2K
High School Magnetic field and generator power output
  • · Replies 5 ·
Replies
5
Views
3K
Graduate Confused, velocity in motional EMF?
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Is electromotive force always equal to potential difference?
  • · Replies 9 ·
Replies
9
Views
2K
Undergrad Is This a Case of Motional emf?
  • · Replies 7 ·
Replies
7
Views
2K