Left mouse drag: Rotate Scroll Wheel-Up: Zoom in Scroll Wheel-Down: Zoom out |
Show magnetic field:
Stop the generator: Voltmeter reading (mV): 0 Rotation per minute (rpm): – magnetic flux, – Electromotive Force |

Magnetic flux through the loop is directly proportional to the area of the loop and magnetic field between two magnets: $$\Phi = \vec B \cdot \vec{S} = BS \cos \alpha$$ Here $\alpha$ is angle between magnetic field and normal vector of the loop. $$\alpha = \omega t$$ Here $\omega$ is angular speed, $t$ is time. According to Faraday's law of electromagnetic induction, electro motive force (EMF) is: $$\mathscr{E} = -\frac{d\Phi}{dt} = -\frac{d(BS \cos \alpha)}{dt} = -\frac{d(BS \cos \omega t)}{dt} = \omega B S \sin \omega t$$ Let $\mathscr{E_\circ}$ denote amplitude of EMF, i.e. $\mathscr{E_\circ} = \omega B S$ Then the last formula for EMF is: $$\mathscr{E} = \mathscr{E_\circ} \sin \omega t$$