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Question
Thu February 10, 2011 By: Akhil Dev

# The length and radii of 3 wires of same metal are in the ratios 2:3:4 and 3:4:5 respectively. They are joined in parallel and included in a circuit having 5A current. Find the current in each case.

Thu February 10, 2011
Dear student,

As resistance is given by,
R = row l/A
= row 4L/(pi D^2)
So, R1:R2:R3 = 2/3^2 : 3/4^2 : 4/5^2

Current is proportional to 1/R, v is constant.

I1:I2:I3 ::9/2 : 16/3 : 25/4

But, I1+I2+I3 = 5

So, I1 = 1.4A,I2 =1.66A, I3 = 1.94A

Hope this helps.
Team
Topperelarning.com
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