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Question 1

Which of the following form of energy is the most expensive for customers?

Answer 1

Electricity

Question 2

In 2023, which of the following sectors in US accounts for the largest fraction of final
(primary + secondary) energy consumption?

Answer 2

Transportation

Question 3

In 2023, roughly what fraction of the US CO2 emission was accounted for by the use of coal alone?

Answer 3

15%

Question 4

In 2023, roughly what fraction of US CO2 emission was accounted for by the use of
petroleum alone?

Answer 4

45%

Question 5

In 2023, roughly what fraction of the US electricity was produced by natural gas?

Answer 5

40%

Question 6

In 2023, roughly what fraction of the US electricity was produced by renewable energy sources (excluding nuclear)?

Answer 6

10%

Question 7

The US CO2 emission reached a peak of 6 billion tons in 2007, and declined to 5 billion
tons in 2022. What was the major reason of the decline?

Answer 7

Increased use of shale gas

Question 8

What is the overall efficiency of the use of all energy (primary + secondary) in US?

Answer 8

35%

Question 9

Who was Arthur Rosenfeld?

Answer 9

He pioneered energy efficiency standards.

Question 10

Which of the following hypothetical models gives a theoretical maximum thermal effi- ciency of any work to be done?

Answer 10

The Carnot Cycle