Question

Observe Fig. Which of these two circuits A or B shows the correct observation?

Answer 1

Observational data

1. There are two halves of potatoes and two circuits.
2. Two terminals of each circuit are inserted on each potato halves.
3. Two greenish-blue spots are found on each potato.

Diagram

Experimental explanation

1. We know, that the bigger line of battery (current source) is positive (+) and the smaller line of battery is the negative (-) terminal.
2. We take an experiment, three potatoes are cut into two halves and the copper wires of a tester are inserted into them.
3. After some time It was noticed that the greenish-blue spots are produced only around the positive terminals, neither on the negative terminals.
4. So, from our observation we can say that all the greenish-blue spots are produced around the positive terminals of the battery which was inserted into the potatoes.
5. This experiment is useful for identifying the positive terminal of a battery.

So, observation A is the correct observation. Greenish-blue spots are produced around the positive terminals of the battery which was inserted into the potatoes.