Hi had a mate ring me today said he had a circuit made with a 12 volt power supply, a led, a 220ohm resistor and a push switch to turn it on and off when testing with multimeter black lead on ground and push button not pressed so led is not lighting tested circuit with red lead first put red lead to just after resister and got 12 volts like we should then put red lead to anode of led and again got 12 volts like we should but then put red lead of meter to cathode and read 10 volts and led is on very dim when I would of though we should either get 0 volts or else 12 volts and no led on .Can someone please explain why this is to me and sorry if this is a basic question just can find this explained any where all info is with circuit running.
