A lamp transfers energy while charge keeps circulating — Physics & Environmental Science

A closed circuit already contains mobile carriers. Current measures charge crossing a branch section per time; voltage measures energy per charge between two points. A lamp can receive energy without using up charge, so the steady current returning through an unbranched loop matches the current entering it. Conventional current and metal-electron drift have opposite directions.

Trace nodes before applying a formula. Series components share one unbranched current path; parallel branches share a pair of nodes and therefore a potential difference in the ideal-wire model. The current rule expresses charge balance and the loop rule expresses energy per charge. Some networks need general node/loop equations rather than repeated series/parallel simplification.

Magnetic interactions and induction add distinct questions. A moving charge’s force depends on a vector cross product, magnetic flux includes orientation, and changing linked flux can produce emf. A stationary unchanged magnet/coil arrangement does not continuously supply electrical output. State the energy input and conducting path; distinguish an interaction-arrow template from a completed current, field or induction model.