Power a laser from Arduino using a audio cable/ jack plug?
Yes it will work. 5V 10mA is 50mW, and pretty much any off the wall audio cable can carry that. Keep in mind that TS, TRS, and TRRS plugs and jacks are not designed for carrying power. When you plug the cable in, the tip will make a connection on each jack conductor, and that the conductors can short to each other. If you do want to use it, it's recommended that power be off before plugging it in or out.