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

# Investigate the relationship between the variables V, R, and I in an electric circuit.

Extracts from this document...

Introduction

Experiment 3: Ohm’s Law                                                                    Date: 22.03.2004

Objective: 1) To investigate the relationship between the variables V, R, and I in an

electric circuit.

2) To analyze series and parallel connection in terms of V, R, I

3) To determine the relationship between current and voltage in a circuit that

contain a filament bulb

Theory:

It is known that electrons flow through a conductor metal wires with an ease without any resistance. This means that nothing would prevent the flow of the electrons. In a normal case however, under normal conditions, a resistance in the wire would affect the flow of the electrons in much the same way that friction slows down a sliding box on a platform. To allow more electrons to move against the resistance of a wire, it is necessary to apply a potential difference between the two ends. One can calculate the potential difference needed to create a current, I if the constant resistance, R of the wire is known. The relationship between these three variables (R, I, V) is given through Ohm’s Law which stated that the potential difference, V in a wire is proportional to the current, I if the temperature and all other physical quantities are fixed. From the law itself, we have an expression:

V=IR

Middle 1. The resistor is remove the next one used is chosen. The voltage is recorded in Table 1 as in step 5. The process is continued until all the resistors’ voltage recorded.

Part 2: Resistance in circuits

1. Three resistor of the same value is chosen. The set of colours is recorded in Table 2.
2. The coded value of the resistors is determined and the value is recorded in the column labelled “Coded Resistance” in table 2. The tolerance value is entered as indicated by the colour of the fourth band under “tolerance”
3. The multimetre is used to measure the resistance of the three resistors. The value is then recorded in Table 2.
4. The percentage experimental error for each resistance value is calculated and is recorded
5. The three resistors are connected to the series circuit by using the spring clips on the Circuit Experimental Board to hold the leads of resistors together without bending them. The resistance of the combination is measured as indicated on the diagram by connecting the leads of the Multimetre between the points at the end of the arrows. 1. A parallel circuit is constructed by using the combination of the two resistors and finally by using all the three resistors. The values for the circuits are measured and recorded.

Part 3: Voltage in circuits

Conclusion

In part 2, the coded tolerance for the resistor is +5%. From the reading we obtain the percentage of errors is 1% and 2%. Thus it said that the data obtain is acceptable. In part 2, we conducted two experiment whereby in one experiment the resistor is arrange in series and in the other experiment the resistor is arrange in parallel. Base on the theory for series resistor we have: Thus the equivalent resistance in the circuit is: The rule for the total resistance when the resistor is arranged in parallel is as followed: As a conclusion we can say that the data obtain in the experiment obey the rule.

In part 3, we found out that the voltage gets distributed in a series circuit with equal resistance when the value of the resistor is the same. The larger the value of the resistor, the larger the value of the resulting voltage.

In part 4, a voltage versus current was obtained. At a certain point in the graph, a straight line is obtain which directly prove Ohm’s Law which stated that the voltage, V is proportional to the current, I and the slope of the graph is the resistance.

Conclusion

As a conclusion, we found out that the voltage, V is proportional to the current, I. The relationship for the variable V, I, R is V = IR

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. ## Investigation into the resistance of a filament lamp.

Average Current(amps) Power(Watts) 0.50 0.49 0.25 1.00 0.60 0.60 1.50 0.67 1.00 2.00 0.70 1.39 2.50 0.76 1.89 3.00 0.91 2.72 3.50 0.96 3.37 4.00 1.06 4.23 4.50 1.10 4.94 5.00 1.11 5.55 5.50 1.21 6.66 6.00 1.23 7.36 6.50 1.27 8.28 7.00 1.32 9.24 7.50 1.41 10.55 8.00 1.46

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

The scale of the spring balance is not firmly attached to the balance. When we pull the spring balance and hence the blocks, there must be vibration of the balance. The scale then is not set to zero. The reading we taken will be inaccurate and then inaccurate calculated values

1. ## Investigating electric potential between two parallel plates and around a charged sphere using a ...

the deflection of the leaf remains unchanged, the electric potential shown remains 3.5kV. - When the flame probe is moved away, keeping it at the same level as the centre of the sphere, the deflection of the leaf decreased from 3.5kV to 1.1kV.

2. ## Is polymer electronics the future of TV screens

electronic ink in different printing processes, like the conventional printing of newspapers. This makes it possible to produce electronics in a continuous printing process, without have many different machines and assembly lines, onto a flexible substrate. This means that the total cost of production for each screen is a lot less than the conventional screen.

1. ## Objective: l To rectify ...

compared with the smoothing inductor, so most of the ripple disappears across the smoothing capacitor. This is the filtered and smoothed full-wave rectification. Procedure: Half-wave rectifying circuit 1. Set up the apparatus according to Figure C25.5 for testing the operation of the half-wave rectifying circuit.

2. ## Sensors cwk. The aim of this coursework is to construct a potential divider circuit ...

If we now increase the distance by 10cm to 0.20m the light intensity should be 1/4 in arbitrary units according to the inverse square law. If we them triple the distance to 0.30m the light intensity will be 1/9 arbitrary units and so on.

1. ## resistivity if a nichrome wire

This is because when squaring the radius of the wire the error of the area also doubles. Therefore most of my error comes from this part of the calculation. Due to all these errors my experiment was not 100% accurate.

2. ## Diode Application in Rectifier Circuits

As Vin becomes negative, the capacitor acts as a battery of the same voltage of Vin. The voltage source and the capacitor counteract each other, resulting in a net voltage of zero as seen by the load. • Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to 