# Magnetic Field in a Slinky

1. Jun 10, 2007

### torquey123

I'm trying to do this lab in physics where we are using sensors to find the magnetic field within a slinky with a current flowing through. Our graph(of time vs.magnetic field) keeps coming out as a sine wave. Is the wave equation for an electromagnetic wave applicable to find the magnitude of the magnetic field? My teacher and I are both a little bit confused, so some guidance would be appreciated. Thanks!

2. Jun 11, 2007

### ice109

did you plug the slinky into the wall ? the mains power supply is alternating current.

the b field inside the coil is approximated by

$$B= \mu _o I N$$
where N is the number of turns and I is the current. in an AC circuit I would be

$$I_o = \frac{V_o}{|z|}sin(\omega t +\phi)$$ where $$\phi$$ is determined by
$$\phi = tan(\frac{\chi_L}{R})$$
and
$$\chi _L = \omega L$$

if you don't understand of this say so and i will try to explain

Last edited: Jun 11, 2007