點解雀仔企係高壓電纜唔係死?(物理電學)

Since I=V/R
("V" represents the potential difference acorss the two legs
(two points) of the bird)
The potential difference is very small since the large voltage of the
cable is in fact the p.d. between the two ends of the cable. A cable
is very long, a few km.
You can calculate the p.d. across two points on the cable by ratio:
V(p.d. across two points)=V(the voltage of the cable)*s(distance
between the two points)/s(length of the whole cable)

As the bird has a large resistance and V is very small, current flow
through the bird will be very small which will not kill the bird.

If the bird has one leg contacting the cable and another one on the
ground, the bird is earthed and this time the potential difference is
very large and current will flow through the body to the ground
(the ground has 0 potential)
With high potential, a large current flows through the bird and kill it.

For the reason of why a large current flowing through the body will
kill it, it is because the large current will stimulate the heart (MAY
BE it is also the reason why doctors use a device to draw current in
the body with the heart failed to bit) and make the heart stop bitting.
That is, the body will get an electric shock and died.

Human is always earthed as we are standing on the ground all the
time, the p.d. must be always very large and thus kill the human.

i have a classmate called handsome too... are u andy wu... (wa ying)

電致死原因係電阻, 電流通過電阻大既物件就會產生熱

當大量(高壓)電流通過人體, 產生既熱力就會燒毀人體

If there have current電流, it should have potential different電壓.

As the bird's foot has the same voltage with wire there will only have few

current pass thourgh it's body.This kind of little current,of course, it will not

make the bird die!

About the human body~

Of course human's resistance電阻 are bigger than bird~ BUT HUMAN ARE

EARTHING----->HAVE POTENTIAL DIFFERENT WITH WIRE!

So there have a large current pass thourgh human body and get a electric stock

and die too~~