Objectives

1. To determine the power of the circuit at different resistance intervals.

2. To prove the value of power using different formulas.

3. To determine the maximum power transferred.

List of Instruments

Personal Computer

Tina (Software)

Ammeter

Voltmeter

Power meter

Wiring Diagrams

+

VS1 9

R1 470A+

AM1

V+

VM1

+

+ WPM1

R2

10

0

24.93mW

1.58V

15.79mA

Data Sheet

RL (Ω) I (mA) VPOWER

VI I2RL V2/RL W (mW)100 15.79 1.58 24.9482 24.9324 24.964 24.93200 13.04 2.87 37.4248 37.4092 37.4405 37.43330 11.25 3.71 41.7375 41.7656 41.7094 41.77470 9.57 4.5 43.065 43.0449 43.0851 43.09680 7.83 5.32 41.6556 41.6901 41.6211 41.651000 6.12 6.12 37.4544 37.4544 37.4544 37.48

Sample Computations (@ 100 Ω)

VI = (15.79) (1.58) = 24.9482 mW

I2RL = (15.79)2 (100) = 24.93241 mW

V2/RL = (1.58)2 / 100 = 24.964 mW

Graph

Maximum Power Transfer

0

10

20

30

40

50

0 200 400 600 800 1000 1200

RL (Ω)

Po

wer

(m

W)

Analysis

Power in this experiment was measured in different intervals of resistance using a watt meter and is computed using different power formulas. Here then maximum power is obtained which is obviously the value with the highest number. This can also be proven or obtained by making a graph of power vs. time. 43.09 mW is thus the maximum power. Noticed that it was calculated using a resistance of 470 ohms which is also the internal resistance of the circuit.

Conclusion

Measuring power in AC circuits was measured at different resistances. Power is checked to be correct using a variety of power formulas. Maximum power was measured at a given resistance and generally it is the internal resistance.