Some newcomers are shocked when they learn about a zero ohm (0R) resistor. These curiosities do actually come in handy for practical electronics design. Here are five good examples. Bridging over tracks In some electronics design cost is a major constraint to balance, along with circuit function. To reduce costs, reduced layer counts may be employed, e.g. two layer or even single layer PCBs. Take the single layer scenario. The layout of the components may be such that the resulting tracking is impossible. A 0R resistor 'cheats' the single layer constraint by bridging one track over another. Component values to be determined Sometimes component values aren't known until the circuit has been built. A good example of this is an antenna matching network. It can be difficult to simulate the entire product (electronics and mechanicals) to gauge the feedpoint impedance of the antenna. Instead, a generic matching network is designed in, using 0R resistors as placeholders. For s...