# Rotation Rate of a Generator Coil

1. Feb 7, 2010

1. The problem statement, all variables and given/known data
If the rotation rate of a generator coil is doubled, what happens to the peak emf?

2. Relevant equations

3. The attempt at a solution

I think it stays the same. Am i right?

2. Feb 7, 2010

### xcvxcvvc

no. look at the equation for induced emf...

3. Feb 7, 2010

4. Feb 7, 2010

### xcvxcvvc

5. Feb 7, 2010

I dont even have a number in my word problem..How can I not use intuition..lol

6. Feb 7, 2010

### xcvxcvvc

by doing it symbolically, and you do have a number: 2

the new $$\omega$$ is twice that of the old $$\omega$$

$$V_{max}$$ is whenever the trig function on the right is equal to 1. Therefore, we can say this:
$$V_{oldmax}=\omega BA$$
$$V_{newmax} =2\omega BA$$
Do you see a substitution?
$$V_{newmax} =2V_{oldmax}$$