821.1 Faraday's law of electromagnetic induction 2. Electromotive force-emr ←⊕ F←田 K R purpose of emf: supply a nonstatic electric force to move the charge keep the potential difference of the two plates and the current in the circuit 821.1 Faraday's law of electromagnetic induction Mechanisn F ×/ak4F田 The work done by Fk opposing Fe converse the energy in other forms into electric K R energy Outside the F move +g from positive plate to negative plate nside the e circul el>e move +q from negative plate to positive plate2 2. Electromotive force-emf Fe← ⊕ r ← ⊕ Fe r + − K R ←⊕→ Fk r Fe r Fe r ← ⊕ Fe r ← ⊕ R purpose of emf: supply a nonstatic electric force to move the charge, keep the potential difference of the two plates and the current in the circuit. §21.1 Faraday’s law of electromagnetic induction Mechanism: The work done by opposing converse the energy in other forms into electric energy. Fe r Fk ← ⊕ r Fe r ← ⊕ Fe r + − K R ←⊕→ Fk r Fe r Outside the circuit： Fe r move +q from positive plate to negative plate Inside the circuit： Fk Fe r r > move +q from negative plate to positive plate §21.1 Faraday’s law of electromagnetic induction