On the average the ampere-hour efficiency of an Edison cell is about

40%
60%
70%
80%

The correct answer is: B. 60%

An Edison cell is a type of primary cell battery that was invented by Thomas Edison in 1899. It is a non-rechargeable battery that uses a zinc anode, a manganese dioxide cathode, and a potassium hydroxide electrolyte. Edison cells are known for their high capacity and long life.

The ampere-hour efficiency of a battery is a measure of how much electrical energy it can deliver per unit of weight. The ampere-hour efficiency of an Edison cell is typically about 60%. This means that for every 100 ampere-hours of electrical energy that an Edison cell can deliver, it will also weigh about 100 grams.

The other options are incorrect because they are not realistic values for the ampere-hour efficiency of an Edison cell. Option A, 40%, is too low. Option C, 70%, is too high. Option D, 80%, is not realistic because it is higher than the theoretical maximum efficiency of a battery.

In conclusion, the correct answer to the question “On the average the ampere-hour efficiency of an Edison cell is about” is B. 60%.