I can think of a few. Uni interview at Cambridge for physics, I was asked to: derive the equation of motion for some coins sliding into each other on a table,

I can think of a few. Uni interview at Cambridge for physics, I was asked to: derive the equation of motion for some coins sliding into each other on a table, and identify the oscillatory nodes of a tea cup struck with a spoon. Needless to say I didn’t get in and have the utmost respect for those who did! First technical job interview I was asked whether a heavy or light element is better for absorbing nuclear radiation. Now that one I am embarrassed I didn’t get having completed my physics degree. Lighter is better.