Question

The greenish blue color spot on the potato is useful in identifying:
A.The positive terminal
B.The negative terminal
C.Both A and B
D.Neither A nor B

Answer 1

When wire is connected to potato, the electrons flow from negative to positive terminal and at only 1 terminal there occurs a reaction with the electrons which results in greenish blue color spot of the potato on that particular site. This information is sufficient enough to answer the question if analyzed properly.

Step by step explanation:
In the given question, it is asked about the potato conducting experiment in which we make a basic battery from potato which can pass electricity and can glow a tiny bulb when connected to wires.
We will see all about this experiment and in between only the answer will be provided after understanding the whole concept.
In commercial batteries used in daily life, electricity is produced by an electrolytic solution and in potato experiment since potato contains components like proteins, carbohydrates, starch, minerals etc. which help in conducting the electricity. Now when the wire is connected to the 2 ends of potato (generally copper wire is used), what happens is electrons go towards the negative terminal of the wire when small amount of electricity is passed and those electrons at negative terminal results in electrolysis of the material contained inside the potato and as a result more electrons are generated.
Now these all the electrons will go towards the positive terminal of wire (because electrons in current flows from negative to positive terminal) and when they reach positive terminal, there is copper wire present and small amount gets reacted with the negative species which ultimately results in change in color and therefore, on reaction with copper wire it becomes greenish blue color spot which is the positive terminal.
Therefore, the correct answer is A i.e. the positive terminal.

Note: This is the experiment-based observation which is known when either any video of this experiment is shown or performed by the student. Also, there are few other important experiments as well in chapters like electricity, electrostatics etc. So, all those experiments and basic conceptual knowledge helps in answering such types of questions.