We use cookies to give you the best experience possible. By continuing we’ll assume you’re on board with our cookie policy

Laboratory Investigation into the Resistance of a Filament Bulb Essay Sample

The whole doc is available only for registered users OPEN DOC

Get Full Essay

Get access to this section to get all the help you need with your essay and educational goals.

Get Access

Laboratory Investigation into the Resistance of a Filament Bulb Essay Sample

Aim: Does the resistance of a filament bulb change as the bulb gets brighter?

Hypothesis: I believe that a filament bulb will have an increasing resistance depending upon the current passing through it.


*Power Supply




*Filament bulb with holder

*Alligator clips



1.Set up the circuit according to the schematic diagram

2.Use the alligator clips to connect the filament bulb to the voltmeter

3.Connect the power supply to the electricity

4.Make sure the switch is closed.

5.Measure and note down the temperature of the bulb with the thermometer

6.Turn on the power of the power supply

7.Measure down the P.D (v) and Current (a) and the temperature as you increase by .50 each time until 4.50 volts



Controlled Variables: Filament bulb of the same type

Independent Variables: Voltage

Dependant Variable: Current (that is what was measured due to the voltage change), Temperature (increased as bulb got brighter)


P.D. voltage

(v)Trial 1 Current (a)Trial 2 Current (a)Average Current (a)Trial 1


(Celsius) Trial 2


(Celsius) Average

Temperature (Celsius)Bulb Brightness

(scale 0-10)



I plotted my information on a graph with the P.D. on the Y axis and the Current on the X axis. In this way the slope of the graph is the resistance of the bulb. Looking at my graph I decided that there are thee separate lines that could approximate the graph. The slope of these three lines gives 3 different resistance values for the filament bulb. The resistance of the bulb increases as the current through the bulb increases. From the information of my table from my results I notice that the temperature increase corresponds with the increase in the current passing through the bulb.

My explanation why the resistance change is that as the bulb has more current passing through it, this makes it hotter. This affects the filament molecules which a vibrating at a faster rate taking up more space. This increases the resistance of the bulb since the current has more obstacles in its way.


My hypothesis is correct my resistance changed due to the current passing through the filament bulb. Specifically I could find three regions of resistance in my graph. R1=8.33Ω , R2=25Ω, R3=33.33Ω.


A way to improve this experiment would be to have more data points and increase the voltage by smaller amounts. This would make my graph more accurate in finding the slope. A way that this experiment could be extended is by using different types of filament light bulbs that have different settings for different voltage. I could also increase the potential difference passing through the bulb as an extension. Another way to determine the relationship of the temperature is to heat the bulb in a different matter such as in a oven and seeing how the temperature relates to the resistance.

We can write a custom essay

According to Your Specific Requirements

Order an essay

You May Also Find These Documents Helpful

Roles and responsibilities of data users

In order to successfully gather data from the users, conducting an interview must be a good idea. Hence that may insufficient as users may not able to describe everything by themselves as the ideal meaning may not portrays only by words. So that it is better if the user can be observed while they use an interface they currently use which may portrays much information....

Data Handling - ICT

Choice of Problem When asked to think of ideas to base my ICT course work on I came up with the following; * Make over salon * Modelling agency * School health centre * Job centre * A tracing family trees agency I decided on the job centre for a number of reasons; * This idea was original; no one else in my year was...

Estate Agents - Problems of a Paper...

Introduction An estate agent based in a paper-based office comes across a lot of problems. It necessary to solve these problems and try to bring the system of the basic system and improve to be more efficient and more reliable in a working area. The firm is in an area that is equally part urban and part rural. Further more because of this area people...

Database Analysis and Database Design Project -...

Moving Images operates a DVD library. The library has a large number of titles, each title having at least one copy. Each title falls into a specific category some of these are adventure, thriller, fantasy, action or education. (There are others) All titles are loan only to registered members of Moving Images. Information is keep about the members is only personal details including name, address...

The ICT Theory

Data All the data for the new system will have to be collected together. All the names, addresses and phone numbers of all the client's contacts will need to be put together so that it will be easier to input the data to the new system. To collect the data together there will need to be a data sheet designed. One of the client members...

Get Access To The Full Essay
Materials Daily
100,000+ Subjects
2000+ Topics
Free Plagiarism
All Materials
are Cataloged Well

Sorry, but copying text is forbidden on this website. If you need this or any other sample, we can send it to you via email.

By clicking "SEND", you agree to our terms of service and privacy policy. We'll occasionally send you account related and promo emails.
Sorry, but only registered users have full access

How about getting this access

Become a member

Your Answer Is Very Helpful For Us
Thank You A Lot!


Emma Taylor


Hi there!
Would you like to get such a paper?
How about getting a customized one?

Can't find What you were Looking for?

Get access to our huge, continuously updated knowledge base

The next update will be in:
14 : 59 : 59
Become a Member