Short Circuit.

Basic Electronics
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62

resistance which passes an abnormally high amount of current.

A short

circuit exists whenever the resistance of a circuit or the resistance of a

part of a circuit drops in value to almost zero Ohms. A short often occurs

as a result of improper wiring or broken insulation.

In figure 38 (on the following page), a short is caused by improper wiring.

Note the effect on current flow.

Since the resistor has in effect been

replaced with a piece of wire, practically all the current flows through the

short and very little current flows through the resistor R1. Electrons flow

through the short (a path of almost zero resistance) and the remainder of

the circuit passes through the 10 Ohm resistor and the battery. The amount

of current flow increases greatly because its resistive path has decreased

from 10,010 Ohms to 10 Ohms.

Due to excessive current flow, the 10 Ohm

resistor becomes heated.

As it attempts to dissipate this heat, the

resistor will probably be destroyed.

Figure 39 (on the following page)

shows a pictorial wiring diagram, which indicates how broken insulation

might cause a short circuit.