Lab Report 2

 

Lab Report 2

Electric Circuit Analysis – Analysis – 1  1

Table of Contents Abstract  ........................................................................................................................................................ 2 Apparatus   ..................................................................................................................................................... 2  Objective  ....................................................................................................................................................... 2  Theory  ........................................................................................................................................................... 2  Experimental Verification of OHM’s Law  Law  ................................... ................. ................................... .................................. ................................... ........................ ...... 2 Readings ................................................................................................................................................ 3 Stimulated on Proteus .......................................................................................................................... 4 Graph .................................................................................................................................................... 7 Questions .............................................................................................................................................. 9

Critical Analysis............................................................................................................................................. 9 

Page 1 of 9 

 

Lab Report 2 Abstract: Breadboard was used to draw given circuit to verify OHM’s Law. Given Voltage was applied by DC Power Supply and at different resistances current was measured by Multimeter Multimeter and OHM’s Law was verified.

Apparatus:  

Resistors   Digital Multi Meter  

Connecting Wires

 

Breadboard

 

DC Power Supply

Objective:  

To verify Ohm’s law experimentally and to find the relationship relati onship between voltage, current and resistance in a circuit.

Theory: Experimental Verification of OHM’s Law  Law  OHM’s Law states that the voltage across the resistance is directly proportional to the current flowing through it. Mathematically, Or

 ∝    =  

where R is the resistance of current and it if the property to oppose current in circuit. OHM’s law states if the current increases the voltage decreases provided the resistance constant. Those materials which obeys OHM’s law are ‘ohmic ohmic’’ or ‘linear’ ‘linear’  because the value of PD varies linearly when current flows through it while others are called non-ohmic.

Page 2 of 9 

 

Lab Report 2 Procedure: 1.  Draw the given circuit on Breadboard with resistors of 2.2k Ω, 4.6kΩ, 6.79Ω respectively one

 by one and supply the voltage of 10V from DC Power Supply first and then different values voltages. 2.  Then use the multimeter as an Ammeter to measure the dc current through the resistor. 3.  Measure the current through the resistor from opposite direction and

10V

verify that measured and calculated currents are approx. same. 4.  Measure the current from different values of resistors and voltage.

5.  Also calculate value of current using OHM’s Law on different resistors and voltages. 6.  Stimulate circuit with different values of resistors and voltages on Proteus. 7.  Record all values on table.

Readings: R = 2.2k Ω 

V (volts)

de )

t

de )

)

ae

m(

uc

t

de m( u

m(

) r A

al A

us m( I

R = 4.6K Ω 

M

I C

a

l

A I

de )

t

de )

)

ae

m(

uc

t

de m( u

m(

r A

al S

mi I

R = 6.79K Ω 

al A

M

us I

A l a C

) t

de )

de

ae

m(

uc m(

u

r A

al I

de

S

mi I

M

t

al A

us I

al

C

a

l

A I

0.5

0.261

0.227

0.23

0.124

0.108

0.11

0.09

0.07

0.07

1.0

0.463

0.455

0.45

0.230

0.217

0.22

0.15

0.147

0.15

1.5

0.709

0.681

0.68

0.332

0.326

0.33

0.23

0.22

0.22

2.0

0.904

0.909

0.91

0.449

0.435

0.43

0.31

0.29

0.29

2.5

1.137

1.136

1.14

0.557

0.543

0.54

0.38

0.37

0.37

3.0

1.333

1.364

1.36

0.667

0.652

0.65

0.46

0.44

0.44

3.5

1.566

1.591

1.59

0.775

0.760

0.76

0.53

0.52

0.52

4.0

1.785

1.818

1.82

0.882

0.870

0.87

0.61

0.59

0.59

4.5

1.989

2.045

2.05

0.988

0.978

0.98

0.68

0.66

0.66

5.0

2.32

2.273

2.27

1.113

1.087

1.09

0.74

0.736

0.74

Page 3 of 9 

S

mi

 

Lab Report 2

Stimulated on Proteus: For R = 2.2kΩ 2.2kΩ 

V = 1V

;

I = 0.45A

V = 3.5V

V = 4V

;

I = 1.82A

V = 5V

Page 4 of 9 

;

;

I = 1.59A 

I = 2.27A 

 

Lab Report 2

For R = 4.6kΩ 4.6kΩ 

V = 1.5V

V = 4V

;

;

I = 0.33A

I = 0.87A

Page 5 of 9 

V = 3V

;

I = 0.65A 

V = 5V

;

I = 1.09A 

 

Lab Report 2

For R = 6.79kΩ 6.79kΩ 

V = 0.5V

V = 3V

;

;

I = 0.07A

I = 0.44A

Page 6 of 9 

V = 2.5V

;

I = 0.37A 

V = 4.5V

;

I = 0.66A 

 

Lab Report 2 Graphs:

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Lab Report 2

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Lab Report 2 Answer the following Questions: 1)  What would happen if a wire having no resistance at all (0 Ω) was connected directly across the terminals of a 6 volt battery? How much current would result, according to Ohm’s Law?   6V

+ -

 

Answer: a)  If a wire having no resistance at all is connected to the terminals of 6 volt battery, than the circuit is said to be short and maximum current will flow through it.   b)  If there is no Resistance in a wire than according to OHM’s Law,  Law, 

 =    or  =  /   Putting R=0 & v = 6V in above equation than, current would be,  = 6/ 0  = ∞, it means maximum current will flow through the circuit and a nd the circuit is said to be a Short Circuit.

Critical Analysis Conclusion: Resistors of different resistances were taken to verify the ohm’s law. On breadboard circuit was drawn and then analyzed by applying different voltage. The current was measured with the DMM used as an Ammeter in milliAmpere. The Current calculated calcu lated by OHM’s Law and measured by DMM were than compared and both values are almost same. After finding current on different voltages and Resistance, we further verified the values on Proteus too. The values of current varies negligibly. After all the experiment, experiment, OHM’s Law was verified by making graph, Voltage on X-axis X -axis and Time on Y-axis. The Graph was of almost linear or straight line means that the material is ohmic because it obeys OHM’s law. As, it follows OHM’s law thus it will also obey all its laws and principles.

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