Two identical copper rods have the same length but different cross-sectional areas

PHYSICS · Single correct · AP · Physics 2: Algebra-based · Thermodynamics · Thermodynamics

Problem

Two identical copper rods have the same length

L

but different cross-sectional areas. Rod 1 has area

A

and Rod 2 has area

2A

. A temperature difference

\Delta T

is maintained across each rod. Which of the following correctly gives the ratio of their conduction rates,

\left(\dfrac{Q}{\Delta t}\right)_2 \big/ \left(\dfrac{Q}{\Delta t}\right)_1

? (a)

\dfrac{1}{2}

(b)

\sqrt{2}

(c)

2

(d)

1