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Grade 12General Physics

TWO UNIFORM WIRES A & B OF SAME METAL AND HAVE EQUAL MASSES, THE RADIUS OF WIRE A IS TWICE THAT OF B. THE TOTAL RESISTANCE WHEN IT IS CONNECTED IN PARELLEL? sir pls write the complete solution..........

Profile image of BHAVANA RM
11 Years agoGrade 12
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1 Answer

Profile image of Abhishek Kumar
11 Years ago
Let the resistance of wire A is RA = \rhol/A
As mass is same, means Volume of the two must be same, since same material implies same density. So, If Area is half for B, its length must be double.
Since, area of cross section of B is twice of A, RB = \rho 2l/(A/2) = 4RA
So, Req = 4/5 RA