亨
=
亠
+
口
+
了
:
Mnemonic symbol: American scientist Joseph Henry.
Before Henry (亨) invented inductance he used to hang out with Hamlet (h) a lot in front of the engine ((e)ng1). One day he observed Hamlet shifting a mandarin (口) from a price cup (了) to a beret (亠) and vice versa, which gave him the idea of putting an iron core into an electromagnet.
月
=
⺆
+
二
:
Yu the Great (yu) is modelling a moon (月) in the elevator's bathroom (e4). He uses a stapler (⺆) to staple a lot of capacitors (二) together to form a moon shape, while the real moon is sitting for him.