If lightning comes down the side of the tree, a portion can jump over to the per

Question

If lightning comes down the side of the tree, a portion can jump over to the person, especially if the current on the tree reaches a dry region on the bark and thereafter must travel through air to reach the ground. In the figure, part of the lightning jumps through distance d in air and then travels through the person (who has negligible resistance relative to that of air). The rest of the current travels through air alongside the tree, for a distance h. If d/h = 0.427 and the total current is I = 5120 A, what is the current through the person?

Explanation / Answer

We have to condsider the two paths as having resistances R1and R2
proportional to the length of the path(air). The resistanceof the man is negligible.
So we have two resistors in parallel between A andB(ground).
Let I1 and I2 be the current through the man and through thetree respectively.
VAB = I1.R1 =I2.R2

R1/R2 =I2/I1
Also R is proportional to length of air path
R1/R2 = d/h = 0.427
Hence, I2/I1 = 1/R2 = d/h = 0.427
I2 =0.427 I1
But I2 +I1 = 5120 A
Combining, I1 + 0.427 I1 =5120
I1 = 5120/1.427 = 3587.94 A

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