GATE AG 2007 • Q58 MCQ • 1 Mark

Section 6: Agricultural Process Engineering

Evaporation and Drying

Subtopic: Drying kinetics

Question Statement:

At 65 °C, Henderson constants C and n are 7.4 × 10⁻⁴ K⁻¹ and 0.56 respectively. The equilibrium moisture content corresponding to 40% relative humidity is

Options:

  • (A) 38%
  • (B) 78%
  • (C) 87%
  • (D) 358%

Official Answer Key:

D

Step-by-Step Solution & Explanation

Henderson equation: 1−RH = exp[−C·T·Mᵉ^n] (T in absolute temperature). T = 65+273 = 338 K. M_e = [−ln(1−RH)/(C·T)]^(1/n) = [−ln(0.60)/(7.4×10⁻⁴×338)]^(1/0.56) = [0.5108/0.2501]^1.786 = (2.0424)^1.786 = ≈3.58 = 358% (dry basis).

Practice This in Real CBT Exam Interface

Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.

Launch CBT Mock Test