1. Fill in the gaps for the unknown Voltage and current readings
G10 – for a S & P circuit know about I & V b)
G11 - for a S Ω P circuit know about:
I, V I R
R calculations
Complex S & P circuits c) d) e)

2. Success criteria…
Can YOU determine the current in each branch and Voltage drops across each resistor?
G11: What is voltage drop (or potential difference) across each component and the current in each circuit branch?

3. Simple Series Circuit
RT = 60 W
Cut the resistor into
three equal lengths
and then separate.
IT = 2 A
VT = 120 V

4. Simple Series Circuit
RT = 60 W
I1 = 2 A I2 = 2 A I3 = 2 A
R1 = 20 W R2 = 20 W R3 = 20 W
V1 = 40 V V2 = 40 V V3 = 40 V
IT = 2 A
VT = 120 V

5. V & I in a (series) circuit

6. Equivalent Series Resistance
12 W a b
4 W
8 W a b

7. Ex:
47  V
28 
The current through the 47  resistor is 0.12 A Calculate the voltage V of the battery.

10. Parallel Circuit
RT = 60 W
IT = 2 A
Cut the resistor
in half and
then separate.
VT = 120 V

11. Parallel Circuit
RT = 60 W
IT = 2 A
VT = 120 V

12. Equivalent Parallel Resistance
6 W
30 W a b
5 W a b R1
For two Resistors in Parallel R2 a b

14. Ex: V
47 
28 
The current through the 47  resistor is .12 A Calculate the current through the 28  resistor.

16. Series / Parallel combinations
5 W
2 W a b
3 W
3 W
6 W a b

17. V & I in a (Parallel) circuit
Why is this model now a fail? :O(

18. How to calculate the equivalent resistance for a group of resistors: