Question

The direction of conventional electrical current is opposite to the direction of the flow of electrons. Choose analogous statement for water:
A. The direction of water flow is opposite to the direction of the flow of negative water.
B. The direction of pressure flow is opposite to the direction of flow of water
C. Both A and B
D. There is no analogous statement possible

Answer 1

Hint: The direction of current is in the direction in which positive charges would flow or opposite to the direction in which negative electrons would flow. But when we see the flow of water it is the flow of mass and mass cannot be negative so, there is no analogous statement.

Complete Step-by-Step solution:
The particles which carry the charges through wires in a closed electric circuit are the negatively charged electrons and they are also called mobile electrons sometimes. Generally, the electric field direction in a circuit is determined by the direction in which positive test charges are pushed in the presence of that electric field. Therefore, these negatively charged mobile electrons always flow in the direction opposite to that of the electric field.
The convention that we use today is that the direction of electric current in a closed circuit is in the direction in which positive charges would flow, developed way back in the past. But we still follow the same convention even today as shown in figure 1.

Figure 1

Therefore, the current in the external circuit is always directed from the positive terminal of the battery and to the negative terminal of the battery, that is the Electrons would flow through the wires in the direction opposite to the direction of the electric field. It is still a bit awkward to use this convention because the actual charge carriers in wires are negatively charged electrons but the direction of the current is determined by the positive charge carriers. Despite this, the convention is used worldwide
Now as we study the flow of Water which is fluid and its flow represents the flow of water molecules. We can also call it the flow of mass. And as we know that there is nothing like a negative mass therefore, there is no analogous statement. Hence option D is correct.

Note: For these types of questions we need to have a clear understanding of directions of different quantities. We should know the direction of the electric field, electric current, and electrons. We also need to know about the flow of water and their direction.