Question Bank • QB_SUB_DFE_TRC_002 NAT • 2 Marks

Section 7: Dairy and Food Engineering

Transient Heat Conduction & Lumped Capacity Analysis

Subtopic: Fourier number definition and Heisler charts

Question Statement:

The Fourier number for transient heat conduction in a slab of thickness $2L = 0.06\text{ m}$ (half-thickness $L = 0.03\text{ m}$) with thermal diffusivity $\alpha = 1.5 \times 10^{-7}\text{ m}^2\text{/s}$ after an elapsed time of $t = 1800\text{ s}$ is:

Answer Key:

0.3

Step-by-Step Solution & Explanation

Fourier number: $Fo = \frac{\alpha t}{L^2} = \frac{(1.5 \times 10^{-7}) \times 1800}{(0.03)^2} = \frac{2.7 \times 10^{-4}}{9.0 \times 10^{-4}} = 0.30$
← Previous (QB_SUB_DFE_TRC_001) Next (QB_EXP_DFE_TRS_003) →

Practice In Authentic CBT Exam Interface

Test your skills under authentic timed conditions with live scoring and AIR percentile ranking.

Launch CBT Mock Test