Simple Resistive Circuits

Transcription

1 German Jordanian University (GJU) Electrical Circuits Laboratory Section 3 Experiment Simple Resistive Circuits Post lab Report Mahmood Hisham Shubbak 7 / / 8

2 Objectives: To learn how to use the kit and TINA software. To apply Ohm's law on simple resistive circuits. Introduction and Theory: Simple resistive circuits are kind of electric circuits which can be simplified into a circuit of one loop. In this experiment we will make three simple circuits consists of voltage source and resistors combined in two ways:. In series: - The same current will go through the resistors. - The voltage drop will divide between the resistors in a direct proportion to their resistances. - We can replace all the resistors with an equivalent resistor whose resistance is given by: eq i. In parallel: - The current will divide between the resistors in an inverse proportion. - The voltage drop across the resistors will be the same. - We can replace all the resistors with an equivalent resistor whose resistance is given by: eq i In all our calculations we will use the Ohm's law: V = I.R This experiment consists of three parts: The first part: Procedure:. Connect the circuit shown in the figure twice: First on TINA simulation software and then on the bread board. Here I used Multisim simulation software instead of TINA.

3 R.kΩ V 5 V R.kΩ.kΩ - Figure -. Measure the theoretical and experimental values of V and I for R, R and. Results: The theoretical and experimental results of this part are shown in this table: Resistors Theoretical Results Experimental Results % Difference Voltage V (V) Voltage V (V) R =. kω % 9.88% R =. kω %.89% R =. kω % 7.865% This figure shows the flow of current through the circuits and the instantaneous voltage and current in some important points. V 5 V V: 5. V I:.53 ma R.kΩ V:.96 V I:.53 ma V:.96 V I:.6 ma R.kΩ V:.96 V I: 893 ua.kω I:.6 ma I:.53 ma I: 893 ua 3

4 The second part: Procedure:. Connect the circuit shown in the figure also twice: First on TINA 3 simulation software and then on the bread board. R kω V V R.kΩ R5 7Ω R kω.kω - Figure -. Measure the theoretical and experimental values of V and I for R, and R. 3. Simplify the circuit using an equivalent resistor. Results: The theoretical and experimental results of this part are shown in this table: Resistors Theoretical Results Experimental Results % Difference (V) (V) R =. kω % 6.9% =. kω % 8.% R = kω %.95% This figure below shows the flow of current through the circuits and the instantaneous voltage and current in some important points. I:.6 ma V V V:. V I:.6 ma I: 3. ma R kω V: 5. V I:.6 ma V: 5. V I:.6 ma R.kΩ I:.6 ma V: 5. V I:. ma I:.6 ma I:.6 ma R5 7Ω I: 685 ua I: 685 ua R kω.kω I:. ma I:.6 ma 3 Here I used Multisim simulation software instead of TINA.

5 We can simplify this circuit into a circuit of one loop using an equivalent resistor as shown in this figure below. V:. V I:.6 ma V V R.7kΩ The third part: Procedure:. Connect the circuit shown in the figure 3 on the bread board. R R kω kω 3 V V Ω 5,, 5 V?? Ω - Figure 3 -. Start with a DC voltage of 5V and increase it till 5V in 5 volt increments. 3. Measure V and I through in each time.. Draw a table of results, then plot the voltage current relationship and find the slope. Results: The results of this part are shown in this table: V source (V) V 3 (V) I 3 R 3 (kω) (calculated) When we plot the voltage current relationship we find that it is a linear relationship as shown below. 5

6 Voltage (V) y =.7356x Current The slope of this line is equal to.735 and according to Ohm's law (V = I.R) it represents the resistance of. When we measure it was equal to.739kω, this means that we have %difference =.5% Discussion We can calculate the values of (V) and (I) for every resistor in part and using the Kirchhoff's laws. In this experiment we had % difference in the values of V, I and R, this might be because one of these reasons:. The resistance of wires used to make the circuits.. The resistance of the used resistors was slightly less than its theoretical value. 3. Systematic errors. Conclusion We can calculate the values of (V) and (I) for any simple circuit using the Kirchhoff's laws.. Kirchhoff's current law: the total current into the node = the total out from.. Kirchhoff's voltage law: the voltage drop through a closed loop = (V is the y-axis, I is the x-axis and R is constant). 6