# Generators (know r, l, B, angular speed of coil) how to find peak EMF?

• michaelw
In summary, the peak emf of the generator can be calculated by using the wire length, loop radius, magnetic field, and angular speed of the coil. By determining the loop area and the number of loops, the peak emf can be calculated as half the product of the angular speed, wire length, loop radius, and magnetic field.
michaelw
The coil of a generator has a radius of 0.14 m. When this coil is unwound, the wire from which it is made has a length of 5.7 m. The magnetic field of the generator is 0.20 T, and the coil rotates at an angular speed of 25 rad/s. What is the peak emf of this generator?

Please help me get started on thsi one :)

i had to do a similar question..
cant remember how i did it though >_<

Knowing the wire length and the loop radius you can determine both loop area A and number of loops N.

Given: $$r = 0.14m, L = 5.7m, B = 0.2T, \omega = 25rad/s$$

$$N = \frac{L}{circumference} = \frac{L}{2\pi r}$$

$$A = \pi r^2$$

$$Emf_{peak} = \omega NBA = \frac{1}{2}\omega LrB$$.

## 1. What is a generator and how does it work?

A generator is a device that converts mechanical energy into electrical energy. It works by rotating a coil of wire within a magnetic field, which creates an alternating current (AC). This current can then be used to power electrical devices.

## 2. What is the relationship between the coil's angular speed and the peak EMF?

The peak EMF (electromotive force) of a generator is directly proportional to the angular speed of the coil. This means that as the coil rotates faster, the peak EMF also increases.

## 3. How do you calculate the peak EMF of a generator?

The peak EMF of a generator can be calculated using the formula E = N * B * A * ω, where E is the peak EMF, N is the number of turns in the coil, B is the magnetic field strength, A is the area of the coil, and ω is the angular speed of the coil.

## 4. What is the significance of r and l in a generator?

r and l, or the radius and length of the coil, are important parameters in a generator as they determine the size and shape of the coil. These dimensions also affect the strength of the magnetic field and the overall efficiency of the generator.

## 5. How can I find the peak EMF of a generator experimentally?

To find the peak EMF of a generator experimentally, you can use a voltmeter to measure the voltage produced by the generator at different speeds. Plotting these values on a graph and finding the highest point will give you the peak EMF value. Alternatively, you can use a multimeter set to AC voltage mode to directly measure the peak EMF.

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