Two metal rods 1 and 2 of same lengths have same temperature difference between their ends. Their thermal conductivities are K₁ and K₂ and cross sectional areas A₁ and A₂, respectively. If the rate of heat conduction in rod 1 is four times that in rod 2, then

Options

(a) K₁A₁ = K₂A₂
(b) K₁A₁ = 4K₂A₂
(c) K₁A₁ = 2K₂A₂
(d) 4K₁A₁ = K₂A₂

Correct Answer:

K₁A₁ = 4K₂A₂

Explanation:

Q = 4Q (Given)
K₁A₁ ∆t / L= 4 K₂A₂ ∆t / L
K₁A₁ = 4K₂A₂