Two metal rods 1 and 2 of same lengths have same temperature

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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

1. K₁A₁ = K₂A₂
2. K₁A₁ = 4K₂A₂
3. K₁A₁ = 2K₂A₂
4. 4K₁A₁ = K₂A₂

Correct Option: B

Q₁ = 4Q₂ (Given)

⇒	K₁A₁Δt	= 4	K₂A₂Δt	⇒ K₁A₁ = 4K₂A₂
	L		L

Q = σeAT⁴