‘Shorts’ in a Parallel Circuit

Suppose a ‘short’ is placed across R3 as shown in
figure 1a above or any other resistor, the circuit will work as though the
‘short’ is connected across the battery and draws infinite current because  the resistance of the wire in used in the
short and all the connecting wires in the circuit becomes negligible. Due to
the infinite current, the wire may get very hot and burn out unless the circuit
is protected by a fuse. The infinite current in the short uses the principle
which states that the rate of flow of current through any branch in a parallel
network of resistors is inversely proportional to their resistance.
Consequently, the current will avoid every other branch due to their high value
of resistance and flow through the short.

1. The short appearing in R3 does
   not mean that only R3 is shorted but both R1 and R2
   are also shorted out. This means that in a parallel network of resistors, a
   short across one branch means a short across all branches. 
2. There is no current flowing through the
   shorted resistors. This means that if they were three bulbs, they will not
   glow. 
3. The shorted components are not damaged. For
   example, if we had three bulbs in figure 1a, the glow again when the circuit is
   restored to normal conditions by removing the short circuit.