- #1

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- Homework Statement
- The generator of a car idling at 1100 rpm produces 12.7 V. What will the output be at a rotation speed of 2500 rpm, assuming nothing else changes?

- Relevant Equations
- ε = N B A ω sin ωt

First I assumed the question asks about max e.m.f so I just used ratio:

output voltage = (2500 / 1100) x 12.7 = 28.9 V, but the answer is wrong.

Then I tried to use the ratio of the whole formula:

$$\frac{\varepsilon_{1}}{\varepsilon_{2}}=\frac{NBA \omega_{1} \sin(\omega_{1}t)}{NBA \omega_{2} \sin(\omega_{2}t)}$$

But I can't calculate because I don't know the value of ##t##.

What is the approach to solve this question? Thanks

output voltage = (2500 / 1100) x 12.7 = 28.9 V, but the answer is wrong.

Then I tried to use the ratio of the whole formula:

$$\frac{\varepsilon_{1}}{\varepsilon_{2}}=\frac{NBA \omega_{1} \sin(\omega_{1}t)}{NBA \omega_{2} \sin(\omega_{2}t)}$$

But I can't calculate because I don't know the value of ##t##.

What is the approach to solve this question? Thanks