The simple CompassMR software allows you to experiment with Magnetic Resonance (MR) used for MRI and NMR. With this, you can demonstrate MR and make it understandable to anyone in a few minutes.
The app can be used to explore Nuclear and Compass MR that are similar except for atomic nuclei not only being magnetic, but also spinning. Static and oscillating fields can be applied to make a compass needle oscillate vigorously, but only if you discover the "resonance condition". The oscillation can subsequently be measured as an induced voltage over a coil. The Fourier transform and the effect of spin can be explored.
Magnetic nuclei are similarly set in motion and detected during MRI, for example. Spin changes the dynamics, but the resonance phenomenon is similar (vibration vs. precession).
The software is mostly tested with newer Android devices. Feedback is appreciated.
Online version: http://drcmr.dk/CompassMR
YouTube demonstration: https://youtu.be/shB8T8cOeas
Explanation and relevance: http://drcmr.dk/MR
The software creator Lars G. Hanson is a senior researcher at the Danish Research Center for Magnetic Resonance and the Technical University of Denmark.
http://drcmr.dk/larsh and http://cmr.elektro.dtu.dk/
MRI: Magnetic Resonance Imaging
NMR: Nuclear Magnetic Resonance