why do birds...

sound familiar? it's the first verse of a song close to you by carpenters. first time i heard it was in 2004 ago. at that time, there was this ceremony in school and the choir perform this song. it was a nice and easy listening one. 

but, have you ever wonder why birds don't get electrocuted when they perched on live wires as shown in this picture?

 

as kids, we're always told not to play near to any utility poles. i always believe that it was dangerous to touch it. i always see birds perching on electrical wires everywhere but somehow i forgot to ask myself why they didn't get shocked until my EMG lecturer mention about it one day. 

so, how come this could happen? when the birds perch on a live wire, their body become charged but with the same amount of voltage in the wire. since, the amount of voltage in the wire and the bird are same there is no current flow. we are to remember that in order for current to flow, there must be a difference between two points of voltage. simple explaination.

however, if one part of the bird touches the ground it will be electrocuted. a ground is a region of approximately zero voltage. therefore, a squirrel can run across an electrical line but die when its foot makes contact with the grounded pole. 

my lecturer told me that if we hang on the wire we'll not die. now i know why playing kite could be dangerous. interestingly, the birds didn't know this but still they didn't die. yeah~