ComputerGeek
Posts: 6
Joined: Tue Aug 23, 2011 4:39 pm

### Don't get my SFQ I was assigned!!!

My science fair question is : What is the effect of the number of wire turns on the strength of an electromagnet?
I don't know the independent or hot to measure it or the dependent. I would also like a brief explanation on what i need to do in order to commence the experiment. Experiments not due for awhile, but i got 2 days to make a data table. HELP!

Craig_Bridge
Former Expert
Posts: 1297
Joined: Mon Oct 16, 2006 11:47 am

### Re: Don't get my SFQ I was assigned!!!

ComputerGeek wrote:What is the effect of the number of wire turns on the strength of an electromagnet?

The independent variable (e.g. what you are going to intentionally change) is the number of turns of wire around some core. It is fairly easy to count the turns so I don't understand your problem with measurements on the independent variable.
The intended dependent variable is the "strength of the electromagnet".

What you haven't covered is the investigational question are control variables (things you need to keep constant to insure a fair test) like the amount of current flowing in the coil, the wire size, the core (material, size, shape), the power source. You also need a way to evaluate/measure the strength of the electromagnet.

You need to do some research (online searching) on electromagnets to get an idea of what core and power source you might want to experiment with and how to measure current for the power source you pick.

You also need to figure out how to measure the strength of the electromagnet. One measure of strength might be how much force it takes to overcome the magnetic attractive force on some object. Other methods might be how many of some object can be lifted.
-Craig

edneu3
Former Expert
Posts: 265
Joined: Wed May 07, 2008 8:36 am
Occupation: Engineer - Product & Technical Development Executive Director

### Re: Don't get my SFQ I was assigned!!!

Studying electromagnets will be a lot of fun. The folks at ScienceBuddies have done a lot of work in this area. Look up this experiment here on the ScienceBuddies web site:

http://www.sciencebuddies.org/science-f ... p035.shtml

You can find another very interesting experiment on magnets at this site:

http://www.sciencebuddies.org/science-f ... p025.shtml

Good luck and HAVE FUN : )
Ed Neu
Buffalo, MN

ComputerGeek
Posts: 6
Joined: Tue Aug 23, 2011 4:39 pm

### Re: Don't get my SFQ I was assigned!!!

So on the link I followed, would i be able to measure the strength of an electromagnet by using paperclips?

Craig_Bridge
Former Expert
Posts: 1297
Joined: Mon Oct 16, 2006 11:47 am

### Re: Don't get my SFQ I was assigned!!!

ComputerGeek wrote:So on the link I followed, would i be able to measure the strength of an electromagnet by using paperclips?

Assuming all your paper clips are identical material and weight, by counting the number of paperclips that a particular experiment is able to pick up and hold, you can compare the "relative" magnetic field strength between the different experiments. It would be hard if not impossible to convert those measurements into scientific units; however, relative results is ususally sufficient if you word your scientific question and hypothesis appropriately.
-Craig