PHY 2020 Lecture Notes - Lecture 33: Sign Convention, Charge Conservation, Ammeter
Document Summary
Like capacitor in the previous chapter, resistors can be connected end-to-end (series) or next to each other (parallel) (a) resistors in series: req= r1+r2+r3+ . (b) resistors in parallel, 1/req= 1/r1+ 1/r2+ 1/r3+ . Analyze the combination of the resistors in the following cirucits. (c) r1 in series with a parallel combination of r2 and r3. (d) r1 in parallel with a series combination of r2 and r3. Example: solve this network of resistors, (a) find the req, (b) the current through each resistor. Many circuit networks cannot be described with simple series-parallel combinations. What then: one method is described by gustav robert kichhoff. Junction: a point where three or more conductors meet: loop: a closed conducting path. The algebraic sum of currents into any junction is zero: this is an application of charge conservation. For example: at junction a in the above circuit: In the calculation, pick a sign convention for the i and stick with it.
