Mechanical Engineering
GATE ME Heat-Transfer PYQs
Build your understanding with focused practice from past exam papers.
Questions 51–54 of 54. Imported answers require independent review unless marked reviewed.
Question 37
Open questionME-1NAT2 marksNeeds review
Two black surfaces, AB and BC, of lengths 5 m and 6 m, respectively, are oriented as shown. Both surfaces extend infinitely into the third dimension. Given that view factor
,
,
,
and Stefan Boltzmann constant,
W/(m
K
), the heat transfer rate from Surface 2 to the surrounding environment is ________ kW. 
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 38
Open questionME-1NAT2 marksNeeds review
Heat is generated uniformly in a long solid cylindrical rod (diameter = 10 mm) at the rate of
W/m³. The thermal conductivity of the rod material is 25 W/m.K. Under steady state conditions, the temperature difference between the centre and the surface of the rod is __________ °C.Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 46
Open questionME-2MCQ2 marksNeeds review
In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40 °C to 80 °C by an oil entering at 120 °C and leaving at 60 °C. The specific heats of water and oil are 4.2 kJ/kg·K and 2 kJ/kg·K, respectively. The overall heat transfer coefficient is 400 W/m
·K. The required heat transfer surface area (in m
) isYour answerChoose one option.
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 47
Open questionME-2MCQ2 marksNeeds review
A metal ball of diameter 60 mm is initially at 220 °C. The ball is suddenly cooled by an air jet of 20 °C. The heat transfer coefficient is 200 W/m
·K. The specific heat, thermal conductivity and density of the metal ball are 400 J/kg·K, 400 W/m·K and 900 kg/m
, respectively. The ball temperature (in °C) after 90 seconds will be approximatelyYour answerChoose one option.
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