Comprehension Check 1.You are given a 12V power supply with a light bulb with a resistance of 6.5Ω; what current flows in this circuit? 2.Using an ammeter, you determine the current in a circuit to be 1.25mA; if the voltage is 9.0V, what is the resistance? 3.You discover that a resistor of 1.5kΩ has 51mA of current; what voltage is involved?

Comprehension Check 1.1.9A 2.7.2kΩ V

Resistor Networks Physics 12

Series and Parallel  What happens when a light burns out in your house?  What happens when a light burns out in a strand of Christmas lights?

Series and Parallel  The two main ways that a constructed is either in series or parallel  More complex circuits will consist of several series and parallel elements and through a simplification process, we can solve the behaviour of the circuit

Series Circuit

Parallel Circuit

Complex Circuit

Network Analysis  Series circuit  Parallel circuit

Simplification  When simplifying a circuit, consider the circuit in multiple steps until you arrive at a final solution with only one effective resistance

Kirchhoff's Laws  1 st Law – The total current flowing into a given point of a closed circuit is the same as the total current flowing out of a given point

Kirchhoff's Laws  2 nd Law – the sum of all voltages within a circuit must be equal to zero

Sample Problem  In the following circuit, if the voltage is 15V and the resistors are 11Ω, 110Ω, 220Ω and 22Ω respectively. Determine the voltage drop across each resistor and the current in each resistor.

Practice Problems  Page 719   Page 724   Page 728  36-37