How do you determine shorted resistor?

A short circuit is an unexpected path of zero resistance between two nodes in a circuit. If you measure the resistance of a resistor, and find that is has zero ohms, but the resistor is supposed to be somthing else, such as 100 ohms, then you can conclude that the resistor is shorted. Keep in mind that the precision of the measurement might be critical. If the resistor is supposed to be 100 ohms, but you get zero ohms, then the answer is easy. If the resistor is 0.001 ohms, but you get zero ohms, then you have to consider the precision of the measurement, the resistance of the wires, etc.