Heat Transfer MCQ’s – Thermal Conductivity of Different Materials
1 - Question
What is the thermal conductivity of asphalt in W/m K?
a) 0.064
b) 0.063
c) 0.062
d) 0.061
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Explanation: Asphalt concrete has three main structural elements i.e. aggregates, binder and the contact layer between them. It is soft at high temperatures but brittle at low temperatures.
2 - Question
Which one is having the highest thermal conductivity?
a) Silver
b) Copper
c) Glass
d) Earth
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Explanation: Thermal conductivity of silver is 410 W/m degree while that of copper, glass and earth are 385 W/m degree, 0.75 W/m degree and 0.138 respectively.
3 - Question
What is the thermal conductivity of magnetite in W/m K?
a) 3.7
b) 3.8
c) 3.9
d) 4.0
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Explanation: This is having low thermal conductivity because of high intramolecular interactions between their outer edge molecules.
4 - Question
Which one is having the lowest thermal conductivity?
a) Furnace
b) Wool
c) Saw dust
d) Glass wool
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Explanation: Thermal conductivity of glass wool is 0.03 W/m degree while that of a furnace, wool and saw dust are 0.30 W/m degree, 0.052 W/m degree and 0.07 respectively.
5 - Question
What is the thermal conductivity of coal in W/m K?
a) 0.25
b) 0.26
c) 0.27
d) 0.28
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Explanation: Coal is composed primarily of carbon along with variable quantities of other elements such as hydrogen, sulfur, oxygen and nitrogen.
6 - Question
What is the thermal conductivity of cotton in W/m K?
a) 0.03
b) 0.04
c) 0.05
d) 0.06
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Explanation: It is a soft material that grows in a protective capsule, around the seeds of cotton plants.
7 - Question
Which one is having the highest thermal conductivity?
a) Brass
b) Aluminum
c) Cast iron
d) Steel
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Explanation: Thermal conductivity of aluminum is 225 W/m degree while that of brass, cast iron and steel are 107 W/m degree, 55 W/m degree and 20 respectively.
8 - Question
What is the thermal conductivity of apple in W/m K?
a) 0.513
b) 0.613
c) 0.713
d) 0.813
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Explanation: It is a sweet fruit that has very low thermal conductivity in order to prevent it from damage
9 - Question
What is the thermal conductivity of ice in W/m K?
a) 1.55
b) 1.66
c) 1.77
d) 1.88
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Explanation: Frozen water in the form of an ordinary household ice cube. The white zone in the center is the result of tiny air bubbles.
10 - Question
Which one is having the lowest thermal conductivity?
a) Ash
b) Ice
c) Freon
d) Water
View Answer
Explanation: Thermal conductivity of freon is 0.0083 W/m degree while that of ash, ice and water are 0.12 W/m degree, 2.25 W/m degree and 0.55 respectively.