Physics Help Forum Frequency of AC Generator

 Electricity and Magnetism Electricity and Magnetism Physics Help Forum

 Apr 7th 2010, 02:57 PM #1 Junior Member   Join Date: Sep 2009 Posts: 23 Frequency of AC Generator The armature of an AC generator has 90.0 rectangular loops each measuring 8.00cm by 12.0cm; the generator has a sinusoidal voltage output with an amplitude of 24.0V. If the magnetic field of the generator is 0.250T, with what frequency does the armature turn? I tried solving this with: E=wNBA*sin(theta) I come up with 111.111s^-1 but the listed answer is 17.7s^-1. Could someone help me with what I might be missing?
 Apr 7th 2010, 07:27 PM #2 Senior Member   Join Date: Dec 2008 Location: Udupi, Karnataka, India Posts: 292 I come up with 111.111s^-1 That value is w = 2*pi*f. Now find f.
Apr 8th 2010, 06:25 AM   #3
Senior Member

Join Date: Dec 2009
Posts: 209

 Originally Posted by chrisfnet The armature of an AC generator has 90.0 rectangular loops each measuring 8.00cm by 12.0cm; the generator has a sinusoidal voltage output with an amplitude of 24.0V. If the magnetic field of the generator is 0.250T, with what frequency does the armature turn? I tried solving this with: E=wNBA*sin(theta) I come up with 111.111s^-1 but the listed answer is 17.7s^-1. Could someone help me with what I might be missing?
Hi there,
I just went through the calculation and I get a radial frequency of 111.111 rad/sec. Radial frequency is the rotational frequency of the armerature in this case. That is how many times per second does the thing rotate.
Frequency is a measure of how many times per second something periodic repeats itself. So the actual frequency is the radial frequency divided by 2pi. If you take the 111.111rad/sec and divide it by 2pi you get 17.7 s^-1.
I'm basically just adding a little to the previous reply, as that person got it right on the nose, so to speak.
Many Smiles,
Craig

 Tags frequency, generator

 Thread Tools Display Modes Linear Mode

 Similar Physics Forum Discussions Thread Thread Starter Forum Replies Last Post BaskinRobbins Energy and Work 2 Apr 5th 2013 01:45 PM LastChance Energy and Work 4 Apr 28th 2012 07:21 AM xtheunknown0 Electricity and Magnetism 2 Aug 5th 2011 11:56 PM rkidcd Electricity and Magnetism 3 Apr 14th 2009 10:44 PM good girl Electricity and Magnetism 1 Jan 2nd 2009 08:43 PM