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Que. The rate of conduction heat flow in case of a composite sphere is given by
a. Q = t₁ – t₂/ (r₂ – r₁)/4πk₁r₁r₂ + (r3 – r2 )/4πk₂r₂r₃
b. Q = t₁ – t₂/ (r₂ – r₁)/4πk₁r₁r₂ + (r3 – r2 )/4πk₂r₂r₃
c. Q = t₁ – t₂/ (r₂ – r₁)/4πk₁r₁r₂ + (r3 – r2 )/4πk₂r₂r₃
d. Q = t₁ – t₂/ (r₂ – r₁)/4πk₁r₁r₂ + (r3 – r2 )/4πk₂r₂r₃
Correct Answer:Q = t₁ – t₂/ (r₂ – r₁)/4πk₁r₁r₂ + (r₃ – r₂ )/4πk₂r₂r₃
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