Practice Emissivity (ε) (2.1) - Radiation Heat Transfer - Heat Transfer & Thermal Machines
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Emissivity (ε)

Practice - Emissivity (ε)

Learning

Practice Questions

Test your understanding with targeted questions

Question 1 Easy

What is emissivity?

💡 Hint: Think of how surfaces emit heat.

Question 2 Easy

What is the range of emissivity values?

💡 Hint: What does a perfect emitter have?

4 more questions available

Interactive Quizzes

Quick quizzes to reinforce your learning

Question 1

What does a blackbody's emissivity equal?

0
0.5
1
2

💡 Hint: Think about what a perfect emitter would be.

Question 2

True or False: A greybody can emit radiation at an emissivity greater than 1.

True
False

💡 Hint: Consider the definition of greybody.

2 more questions available

Challenge Problems

Push your limits with advanced challenges

Challenge 1 Hard

A surface has an emissivity of 0.75 and is maintained at a temperature of 800 K. Calculate how much thermal radiation it emits per square meter using the Stefan–Boltzmann Law.

💡 Hint: Calculate T to the fourth power before multiplying.

Challenge 2 Hard

Discuss how the emissivity of materials in a building can affect its energy efficiency. Provide two examples.

💡 Hint: Think about materials used in heating versus cooling scenarios.

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Reference links

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