Notes

Outline

Technical Physics 2 DC Circuits

Series circuit one continuous path for current to flow two elements have only one common connection

Parallel circuits multiple paths for current to flow two elements have two common points of connection

Internal resistance the resistance within the source of Emf Terminal potential difference (VT) the potential difference measured across the terminals of the source. It will be less than the Emf because of the internal resistance

Kirchoff ’s laws 1.  S Iin  = S Iout    The total current into any junction must equal the total current out of that junction. 2. S Emf  =  S I  R      The sum of the Emf supplied to a circuit must equal the sum of the potential drops within the circuit.

The Wheatstone bridge a circuit used to determine an unknown resistance. The circuit as shown below allows for the adjustment of R1  and R2   to balance the voltage drops across the circuit. Calculations as done in the lab may then be used to determine the unknown resistance.

Wheatstone Bridge  ( schematic diagram)

Wheatstone bridge (Visual Appearance)