# Electromagnetic Induction Help Requested

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1. Mar 21, 2016

### erashish14

Hi Experts,

I'm doing an experiment of Electromagnetic Induction (producing current by changing magnetic field i.e. by circulating magnetic wheel of N52 Neodymium Magnets around copper coil),

but what i found

when the speed of wheel is HIGH, the Output Current is LOW (in range of .02 microAmp) &

when wheel is about to stop i.e. when its speed is LOW, the Output Current is HIGH (in range of .11 microAmp)

check the video once (),

Kindly suggest where i'm doing wrong or what i need to change in my experiment, because as per Faraday's law, more frequent change in magnetic field produces more current, but its not seen in my experiment

Kindly help

Ashish
http://lightenmyways.blogspot.com/

2. Mar 21, 2016

### BvU

Hello Erashish,

Two questions:
1. Are the magnets oriented alternately north-south south-north etc ?
2. Is the meter range set to AC current (and not DC current ) ?

3. Mar 21, 2016

### erashish14

Hi BvU,

1. No magnets are not oriented alternately, they are aligned at same orientation i.e. North-North-North-North at the outer end of circle.
2. Meter is set to DC Current.

4. Mar 21, 2016

### BvU

1. So does the magnetic field through the coil change very much from one magnet passing to the next ? Could that be improved ?
2. Change in the magnetic field causes induced emf. ${ \varepsilon} = -{d\Phi\over dt}$ or something . To get a DC current, $\Phi$ would have to grow linearly and that's not what you can produce !

5. Mar 22, 2016

### erashish14

So what you suggest, what changes i should do, to make the project working ???

6. Mar 22, 2016

### BvU

1. What would cause more change in $\Phi$: north north north etc. passing by or north south north south north ?
2. Try AC volt instead of DC current setting on the meter

In fact I had hoped that these suggestions would have been obvious from the comments I made ...

7. Mar 22, 2016

### erashish14

I will try your both suggestion & let u know the result soon,

Thanks :)

8. Mar 23, 2016

### erashish14

Hi,

I tried putting multimeter at AC volts, but its showing zero reading, maybe because output voltage is too low, as output DC current was in microampere.

I tried with putting load (resistor) at the copper wire ends, to measure output voltage or current, but condition remains the same.

I also tried to put magnets close to each other with opposite polarity, but still condition is same.

Kindly suggest, if anything else i can do, to make experiment working properly.

Ashish
http://lightenmyways.blogspot.com

9. Mar 23, 2016

### BvU

Well, that was the best I could do. Only other thing I can think of is that the windings of the coil are short-circuited. Does the resistance of the coil correspond to the full length of the wire used ?
If you can find an analog $\mu$A meter you could try that.