The charge carried by one electron is e = -1.6 10-19 C. The ...

[cnetterville]

The charge carried by one electron is e = -1.6  10-19 C. The number of excess electrons necessary to produce a charge of 1.0 C is
 
  A) 6.3  1018.
  B) 1.6  1019.
  C) 6.3  109.
  D) 6.3  106.
  E) 1.6  1018.

Question 2

One of the most efficient engines built so far has the following characteristics: combustion chamber temperature = 1900C; exhaust temperature = 430C. 7  109 cal of fuel produces 1.4  1010 J of work in one hour.
 
  (a) What is the actual efficiency of this engine?
  (b) What is the Carnot efficiency of this engine?

[ilianabrrr]

Answer to Question 1

A

Answer to Question 2

(a) 48
(b) 68

[cnetterville]

Thanks for the timely response, appreciate it

[frankwu0507]

Great answer, keep it coming