Magnetic Field |

When you make electricity, where exactly do the electrons come from?

Sunday, June 5, 2011

This was a question from my children and I’m not sure of the answer when I think about it. I know that if you spin a magnet in an magnetic field (or ferrous material work too?) that you’ll produce electricity. Electricity is the flow of electrons. If I think of the large generators that spin [...]

Can inertia of rotation help a generator work in vacuum/space with no fuel forever ?

Friday, June 3, 2011

2 Comments

I guess inertia of rotation allows an object rotate forgood till an opposing effective force finishes it & rotation of armature with coiling produces elctricity in magnetic field .In vacuum conditions ,there can be nothing to oppose . So using the facts can electricity be produced in space forever ? If no why ?

How many turns of copper wire should we use to make an AC electric generator, to obtain…?

Tuesday, May 31, 2011

2 Comments

1. How many turns of copper wire should I use to make an AC electric generator to obtain: (a) 220V/240V AC (b) about 100 Amperes of current 2. The above would be achieved thru using Neodymium Magnets from Hard disk drives, thus pasting the magnets on a CD on the circular diameter edge of the [...]

science help, por favor? please?

Friday, May 27, 2011

4 Comments

Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. The process of generating an electric current by moving an electrical conductor relative to a magnetic field is called (1 point) A. magnetization. B. electromagnetic force. C. electromagnetic induction. D. alternating current. 2. A device that changes [...]

URGENT: Physics Question!?

Monday, May 23, 2011

2 Comments

A circular coil has 275 turns and a radius of 0.045 m. The coil is used as an AC generator by rotating it in a 0.500 T magnetic field. At what angular speed should the coil be rotated so that the maximum emf is 175 V? The answer is supposed to be w = 50 [...]

Science, Electricity, Help Please?

Sunday, May 22, 2011

1 Comment

Number Goes In Blank (1 – 5) ___ Inside The Generator, A Coil Of Wire Surrounded By A Giant Magnet Spins. ___ Power Lines Carry The Electric Current To Local Areas. ___ Water Moves Over The Blades Of A Turbine That Is Connected To A Generator. ___ The Spinning Wire In The Magnetic Field Produces [...]

Chemistry/Physics question help please?

Saturday, May 21, 2011

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In a generator, the current produced in __________ when the loop is parallel to the surrounding magnetic field. a. zero current b. average c. very small d. at a maximum Describe how a step – down transformer works to reduce voltage. Use the vocabulary terms “primary coil,” “secondary coil” and “electromagnetic induction.” A __________ magnetic [...]

Electromag Physics Help?

Thursday, May 19, 2011

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A generator uses a coil that has 120 turns and a 0.65-T magnetic field. The frequency of this generator is 60.0 Hz, and its emf has an rms value of 120 V. Assuming that each turn of the coil is a square (an approximation), determine the length of the wire from which the coil is [...]

How does an alternator works?

Wednesday, May 18, 2011

2 Comments

Hello there, I have done some research on this topic. I know alternator got 2 main parts rotar and stator, my question is about the rotar and stator. I would like to know whether the rotating part is got the rotating magenetic field (if that is the case, is it the magnet permant magnet or [...]

CLiCk ThIs!!!!!!!!!!!!!!! physics help chapter 37 #10,18,21!!!!!!!!!!!!?

Sunday, May 15, 2011

1 Comment

THNX EVERYONE FOR CLICKING THIS! PLEASE ANSWER THESE FOLLOWING QUESTIONS WITHOUT TOO MUCH DETAIL! THNX AGAIN!!! #10) A motor is characterized by three main ingredients: magnetic field, moving charges, and magnetic force. What are the three main ingredients that characterize a generator? #18) Why is it advantageous to transmit electric power long distances at high [...]