1548. Harmonic mean temperature difference is given by September 7, 2025 by Admin √(ΔT₁ . ΔT₂) 2.(ΔT₁ . ΔT₂)/(ΔT₁ + ΔT₂) 2.(ΔT₁ . ΔT₂)(ΔT₁ – ΔT₂) (ΔT₁ – ΔT₂)/(ΔT₁ . ΔT₂) ✅ The correct answer is option B.
