X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f X-Recipient: geda-user AT delorie DOT com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=vKNVANiALYzgyTTO7r7FRLeqshiR53dxxpzhn6HsbbA=; b=vQFocLfZyni2kwp9Nd0pk4IubybVJpjjZArmd1HeTaLQ1JAdmA7dGohbS+QcBJeJx+ TizoS0lI6tN49mVQFsAd7xrJBcC63dJyyI0/h/j25KlkXS16WvBnZoWmcL9WWM9YSLii MFP9C/iXiWGw5MbQZux3awPz2Hy6DvKlwY8wu6yytd6CVTC4PJEaAp/3L1+bZ16nzj1j lmsvalGT5Jf0brmHx7PLVjm4zjZmR8rjwyjOKgswVdU7YZabm6Pu51nsnPe16bcuLda9 fuizvkODLoLtQoX8K5nvobzIU4rkxATxfqK8ur6i2UyR6O5gI64QJxW3O/rYxPJvPX6B rIsw== MIME-Version: 1.0 In-Reply-To: References: Date: Fri, 16 Mar 2012 12:59:21 -0400 Message-ID: Subject: Re: [geda-user] Daughter's Science Fair From: John Hudak To: geda-user AT delorie DOT com Content-Type: multipart/alternative; boundary=0016e6dd98e24325dc04bb5f2112 Reply-To: geda-user AT delorie DOT com Errors-To: nobody AT delorie DOT com X-Mailing-List: geda-user AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk --0016e6dd98e24325dc04bb5f2112 Content-Type: text/plain; charset=ISO-8859-1 The magnetic field needs to be changing in order to induce a current in the other coil. You can do this in two ways: 1) Use a AC power source instead of the DC battery 2) Keep the DC battery, align the second coil and nail combination parallel to the powered coil and nail, and move the second coil up and down parallel to the powered coil. By cutting the lines of magnet flux, and current will flow in the second coil and nail. You may need to wrap a lot more turns on the second nail to notice any current flow. the current flow will be small, as in microamps to maybe 1 millAmp. A physics text book will provide the equations to use to give you guidance on flux calculation, number of turns in a coil, and current that can be induced. The topic you want to investigate is Faradays Law of Induction. Then again, there is probably many similar experiments outline on the web, or you could look up Faradays Law on the web with related examples... Good luck John On Fri, Mar 16, 2012 at 10:02 AM, Rob Butts wrote: > My nine-year-old daughter has a science fair tomorrow. We are doing > simple electromagnets out of nails. We are just using one C battery with > approximately a 30-penny nail and 26 guage wire wrapped around the nail for > two layers. When the battery is connected the nail has a good magnetic > strength in that it will pick up another nail not just paper clips. > > I was thinking about showing how a current in one coil will induce a > current in another (how an electric toothbrush charges). We rigged up > another nail the same way but with a little bulb attached. Check my > theory, shouldn't the electromagnetic field produced by the coil and nail > with the battery induce a current in the other coil when placing the nails > adjacent and parallel? > --0016e6dd98e24325dc04bb5f2112 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable The magnetic field needs to be changing in order to induce a current in the= other coil.=A0 You can do this in two ways:
1) Use a AC power source in= stead of the DC battery
2) Keep the DC battery, align the second coil an= d nail combination parallel to the powered coil and nail, and move the seco= nd coil up and down parallel to the powered coil.=A0 By cutting the lines o= f magnet flux, and current will flow in the second coil and nail. You may n= eed to wrap a lot more turns on the second nail to notice any current flow.= =A0 the current flow will be small, as in microamps to maybe 1 millAmp.=A0 = A physics text book will provide the equations to use to give you guidance = on flux calculation, number of turns in a coil, and current that can be ind= uced.=A0
The topic you want to investigate is Faradays Law of Induction.

Then= again, there is probably many similar experiments outline on the web, or y= ou could look up Faradays Law on the web with related examples...

Good luck
John


On Fri, Mar 16, 201= 2 at 10:02 AM, Rob Butts <r DOT butts2 AT gmail DOT com> wrote:
My nine-year-old daughter has a science fair tomorrow.=A0 We are doing= simple electromagnets out of nails.=A0 We are just using one C battery wit= h approximately a=A030-penny nail and 26 guage wire wrapped around the nail= for two layers.=A0 When the battery is connected the nail has a good magne= tic strength in that it will pick up another nail not just paper clips.
=A0
I was thinking about showing how a current in one coil w= ill induce a current in another (how an electric toothbrush charges).=A0 We= rigged up another nail the same way but with a little bulb attached.=A0 Ch= eck my theory, shouldn't the electromagnetic field produced by the coil= and nail with the battery induce a current in the other coil when placing = the nails adjacent and=A0parallel?

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