Maximum Power Transfer

Statement of purpose
To affirm that the maximum power transfer to a load resistance occurs when the load resistance is the same as the Thevenin resistance of the circuit.

Part A
 
Procedure

Measure the resistance of the fixed resistor.

Resistance = 5.61Ohms

Data 1

Measured values

Measured V0 (V)	Measured Rx (Kohms)	Calculated P0 (W)
2.80+/-.01	14.64+/-.01	0.000536+/-.0000028
2.68+/-.02	13.73+/-.01	0.000523+/-.0000055
2.51+/-.01	12.55+/-.02	0.000502+/-.0000029
2.43+/-.01	12.08+/-.01	0.000488+/-.0000028
2.32+/-.02	11.50+/-.01	0.000468+/-.0000058
2.17+/-.01	10.77+/-.01	0.000437+/-.0000029
1.98+/-.01	10.00+/-.01	0.000392+/-.0000028
1.80+/-.02	9.34+/-.01	0.000347+/-.0000055
1.63+/-.02	8.78+/-.02	0.000303+/-.0000053
1.41+/-.01	8.17+/-.02	0.000244+/-.0000025
1.28+/-.01	7.82+/-.01	0.000210+/-.0000023
0.84+/-.01	6.89+/-.01	0.000103+/-0000017
.02+/-.01	5.65+/-.02	0.00000007+/-.00000
.00+/-.001	5.62+/-.02	~0

Theretical values

using voltage divider,

Theoretical V0 (V)	Theoretical Power (W)
3.25	0.000721
3.20	0.000746
3.11	0.000771
3.07	0.000780
3.03	0.000798
2.96	0.000814
2.88	0.000829
2.81	0.000845
2.75	0.000861
2.67	0.000873
2.62	0.000878
2.48	0.000893
2.26	0.000904
2.25	0.000901

Part B

Procedure

Data 2

	Nominal (kohms)	Measured (kohms)
R1	1	0.966
R2	10	9.85
R3	10	9.86
R4	1	0.976
R5	1	0.979

	Nominal (V)	Measured (V)
Voltage source 1	4.5	4.54+/-.01
Voltage source 2	9	9.05+/-.01

LoggerPro graph

 

Conclusion
The maximum amount of power transfer occurs when the resistance of the load is the same as the Thevenin equivalent of the the network.