Investigation of resistance of Lightbulb

[chipsnfish]

Homework Statement

I am currently carrying out an investigation into all the factors that affect the resistance of a lightbulb. Firstly, I have done a graph to show voltage against resistance for a 24W Lightbulb to see if Watts affect resistance, however my friends and teacher all told me to do it as current against voltage, but what is the point when the investigation is asking me to find out the factors that affect resistance? Also, how does watts affect resistance and what is watts exactly.
Another problem is that I need to have precise and reliable data in order to get the high grades, but I don't know how I can get precision and reliability with just a "power pack, filament lightbulb, wire, variable resistor, two multimeters..."?
Please help, thanks

 

[LowlyPion]

Welcome to PF.

This lecture might be useful at about 17:20 in, though actually the whole lecture might be helpful.:

https://www.youtube.com/watch?v=cJSp8v0YJrA

 

[nlightner]

I can provide some guidance and clarification on your investigation. First, it is important to understand that resistance is a physical property of a material and is affected by several factors, including the material's composition, length, cross-sectional area, and temperature. In the case of a lightbulb, the filament is the material that determines the resistance.

In order to accurately investigate the factors that affect resistance, it is important to use a consistent and reliable method. Your friends and teacher are correct in suggesting to plot current against voltage instead of watts against resistance. This is because watts is a unit of power, which is the product of current and voltage. By plotting current against voltage, you can directly observe the relationship between these two variables and how they affect resistance.

To address your concern about precision and reliability, it is important to carefully design your experiment and use appropriate equipment. The use of a power pack, filament lightbulb, wire, variable resistor, and multimeters is a good starting point. However, it is important to ensure that your equipment is calibrated and functioning properly. Additionally, it may be helpful to repeat your measurements multiple times and take an average to improve precision and reliability.

Lastly, watts is a unit of power and is defined as the rate at which energy is transferred or work is done. In the case of a lightbulb, it is a measure of how much electrical energy is converted into light and heat. It is related to resistance through the equation P=I^2R, where P is power, I is current, and R is resistance. This means that as resistance increases, the power dissipated by the lightbulb also increases.

I hope this helps clarify some of your questions and provides some direction for your investigation. Remember to carefully plan and execute your experiment, and use appropriate methods and equipment for accurate and reliable results. Good luck with your investigation!