• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# The objectives of this experiment are to Verify Kirchhoffs laws Determine the equivalent resistance of a network &amp; Study the maximum power transfer theorem.

Extracts from this document...

Introduction

EE2721 Electric Circuit Analysis

Group 5

Introduction:

The objectives of this experiment are to

Verify Kirchhoff’s laws

Determine the equivalent resistance of a network

Study the maximum power transfer theorem

Apparatus:

DC power supply

Multi-meter (DMM)

Experimental board

Experiment 1:(Kirchhoff’s laws)

Theory:

According to the Principle of conservation of Charges, since charges do not accumulate at any point in a network, the charges cannot be created or destroyed.

This bring the Kirchhoff’s First Law, the algebraic sum of the current at a junction of a circuit is zero. Therefore, the current arriving a junction equals the current leaving the junction. This law also assumed to be positive if it flows into a point and negative if it flows out from the point.

There is also a Kirchhoff’s second law relates the total e.m.f in a closed loop.

Round a closed loop, the algebraic sum of the e.m.

Middle

=21.5Ω

The power supply was removed, we measured again the equivalent resistance =28.4Ω

The result in step 1 is smaller than in step 2.In step 1 , the power supply has not been removed, and it consists internal resistance. As it connects parallel to

the circuit, the equivalent resistance will be smaller than without parallel internal resistance.

The star-to delta or the delta –to –star transformation was used to calculate the equivalent resistance of network shown in figure 3.      equivalent resistance of : The we calculate is close to step 1 but smaller than step 2. When we calculate the equivalent resistance of ,we don’t know the internal resistance of power supply and we assumed the internal resistance is zero and ignore it in calculation, so the result we calculate is similar to data with removal of power supply.

Experiment 3(Maximum power transfer theorem)

Procedures:

The circuit as shown in figure 7 with Conclusion

span="1" rowspan="1">

8.909

9.98

11.198

12.475

14.851 0.55

0.566

0.573

0.587

0.596

0.612

0.609

0.603

0.601

0.600

Maximum power: 0.6127mW 9.2 Total resistance:9.2+10=19.2  =20KΩ(with varying from 15KΩ to 25KΩ) 2.153 2.2155 2.2779 2.3403 2.4028 2.5351 2.5973 2.6597 2.722 2.784 0.142 0.1388 0.1357 0.1326 0.1294 0.1265 0.1236 0.1205 0.1174 0.1143 15.121 15.962 16.786 17.649 18.569 20.04 21.014 22.072 23.186 24.356 0.307 0.308 0.309 0.31 0.311 0.321 0.321 0.32 0.319 0.318

Maximum power: 0.0215mW 20.05 Total resistance:20.05+20=40.05 Discussion:

aI) minimum sources voltage:

V=400x2x =40v

aII) there is not significant risk of this type of accident to occur, as the voltage of personal computer is 17v, it is smaller than the minimum source voltage that can produce electrical shock.

b) The criterion for maximum power transfer from a source to a load is the load resistance equals to the internal resistance of the source. If we are free to select without changing the source voltage, we can decrease the in order to maximize the power delivered to the load.

E=i(R+ iE=  =  = The smaller the , the higher the power supply

C) = = = The maximum power output occurs when = =0 =0 =2R = The maximum power output = = This student written piece of work is one of many that can be found in our AS and A Level Electrical & Thermal Physics section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related AS and A Level Electrical & Thermal Physics essays

1. ## The potato - a source of EMF

layer is formed on the electrodes from the contents of the potato which in turn acts as a barrier increasing the internal resistance. However, this is only a presumption and cannot rely on this as I do not know whether or not the electrodes were cleaned between readings taken at different distances.

2. ## The aim of the experiment is to verify the maximum power theorem and investigate ...

To find out the static friction, we can make use of the following formula: fL = �s R where �s = coefficient of static friction. As the coefficient of static friction is constant, by the formula of the static friction, the magnitude of the static friction is direct proportional to the normal reaction force.

1. ## Find The Internal Resistance Of A Power Supply

E - Ir V = -Ir + E y = mx + c Therefore the gradient (m) is the internal resistance,-r, and the y-intercept is the Electromotive Force (E). Safety Precautions: As we are using mains electricity, we must make sure that no water should come in contact with the

2. ## PID Control Case Study - Balanced beam demonstration

The photodiode is reverse biased (via 200K resistors) to 5V in order to allow a path for dc current produced by background light, to discharge (Diag.4). Diag.3 - Source Diag.4 - Sensor The photodiode current is converted to voltage and amplified by a trans-impedance AN20 CAM (Diag.5).

1. ## Coursework To Find The Internal Resistance Of A PowerSupply

the wires of the circuit, but this could increase if the power supply was switched on continuously for a long period of time. Measurements and Readings That Will Be Taken: I will measure the length of the metal rail and split the length into eight different sections.

2. ## Investigate the maximum power output of a solar cell (photovoltaic cell).

and an ammeter connected to the circuit to measure the current of the circuit. The light shone onto the solar cell will be from a filament lamp, connected in a separate circuit to a power supply, on which I can vary the voltage.

1. ## Investigating the E.m.f and Internal Resistance of 2 cells on different circuit Structures.

I will conduct an investigation on how the e.m.f and internal resistance are influenced by the changing of the circuit and where the cells are positioned, and I will also use external resistors to clearly identify any influences or alterations Hypothesis: For this investigation I have a possible hypothesis which seems plausible using the background knowledge I know.

2. ## How does changing the distance from a light source affect the power output of ...

light is reflected off its surface, and this results in lost energy. Because of this, the cells have an antireflective coating, which cuts reflective energy loss down to 5%. This shows how a PV Cell is made up from its constituents. • Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to
improve your own work 