Ranking Resistances of Cylindrical Resistors · PhysicsBowl 2016 #7
Physics · electromagnetism
Problem
Three cylindrical resistors are made of the same material. The length and radius of each resistor is:
Resistor 1: Length L, radius r
Resistor 2: Length 2L, radius 2r
Resistor 3: Length 4L, radius 2r
Which one of the following choices correctly ranks the resistance of these resistors (R1,R2,R3)?
(A) R1=R2<R3 (B) R2<R1<R3 (C) R3<R2<R1 (D) R1<R2=R3 (E) R1=R3<R2