AP EAPCET 12 July 2022 Shift 2 Paper

Two conductors A and B are made of the same material and have same length. Conductor A is a solid wire of diameter d1, and conductor B is a hollow tube of outer diameter 2.0mm and inner diameter 1.0mm. The resistances of the conductors A and B are R1 and R2 respectively. If ‌

R1

R2

=3 then d1 is