Electric  circuits

 Circuits:

1. Currents are variables       Direction of the currents is like orientation of the coordinate system       After solving Kirchhoff's 1st and 2nd laws re-label the currents to be positive

2. The meaning of equivalent resistance         Resistors in parallel and in series            Network of resistors        Voltmeter         Ampmeter

3. Voltage divider        V1 / R1 = V2 / R2        Measuring light and temperature          Rheostat 

4. Complex circuits