Energy transfer by an electric current

U radu proučavan je prijenos energije u jednostavnim strujnim krugovima. Električno polje unutar i izvan strujnog kruga uzrokuje površinska raspodjela naboja na vodiču, a magnetsko polje uzrokuje struja kroz žice. Pomoću električnog i magnetskog polja kvalitativno je određen Poyntingov vektor u prostoru oko jednostavnog strujnog kruga koji se sastoji od baterije, žaruljice i žica. Iz analize prijenosa energije dobiveno je da se energija odvodi iz baterije, a prenosi se na žaruljicu i putem žica i preko cijelog prostora oko žica. Navedeni su primjeri različitih strujnih krugova u kojima se analitički ili numerički pronašao Poyntingov vektor. Dobiveni teorijski rezultati u skladu su sa eksperimentalnim mjerenjima.In this thesis, we analysed the energy transfer in simple circuits. The electric field inside and outside the circuit is created by surface charges on the conductor, and the magnetic field is created by current flowing in the conductor. Using the electric and magnetic fields we qualitatively determined the Poynting vector in the space around the simple circuit, which consists of a battery, wires and a light bulb. From our analysis of the energy transfer we concluded that the energy is transferred from the battery, and is transferred to the light bulb through the wires and across the entire space around the wires. We described examples of different circuits in which the Poynting vector was found analytically or numerically. The obtained theoretical results are consistent with the experimental results