1. Which of the following metals has the highest thermal conductivity?
(a) carbon steel
(b) stainless steel
(c) aluminum
Answer: (c)
2. The Ellingham diagram
(a) is a plot of thermal conductivity against temperature,
(b) shows the free energy of oxide formation against temperature.
(c) shows the rate of oxidation of metals against temperature.
Answer: (b)
3. True or False?
A metal with a high negative free energy of oxide formation will generallyrequire greater
shielding from the atmosphere during welding.
Answer: True
4. Electricity can be conducted by:
(a) atoms and electrons.
(b) electrons and ions.
(c) only ions.
Answer: (b)
5. Which of the following elements is often present in submerged arc fluxesto improve arc
stability?
(a) copper
(b) potassium
(c) nickel
(d) tungsten
Answer: (b)
6. Thoria is added to tunsten electrodes for what purpose?
Answer: To increasethermionic emission by lowering the work function.
7. True or False?
All pure metals have the same crystal structure.
Answer: False. Metals generally haveone of three basic structures.
8. Which crystal structure(s) is (are) composed of close-packed planes?
Answer: FCCand HCP
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller ExamNavigator. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.99. You're not tied to anything after your purchase.