Question

In an electric circuit containing a battery, the charge (assumed positive) inside the battery
A) always goes from the positive terminal to the negative terminal.
B) may go from the positive terminal to the negative terminal.
C) always goes from the negative terminal to the positive terminal.
D) does not move at all.

Answer 1

Hint: Current always flows from positive terminal (higher potential) to negative (lower potential). However, negative charges or electrons flow from lower potential to higher potential. This means that positive charge moves in the direction of the current.

Complete step by step answer:
A simple device used to supply potential difference in a circuit is called the electric cell. A cell consists of two electrodes dipped in an electrolyte. Two or more cells come together to form a battery.
When we talk about electric current it is the flow of charge. By convention, it is low of positive charge but actually current occurs due to the flow of electrons (negative charge). Whenever a potential difference is applied across two points there occurs the flow of electrons. The electrons start flowing from a lower potential to the higher potential.
The direction of the flow of current is opposite to the direction of the flow of electrons. The electrons flow from negative (lower potential) to the positive (higher potential). So, the current will flow from positive (higher potential) to negative (lower potential).
However, in a circuit, to determine the flow of current we need to know the nature of the circuit as well.
The nature of the circuit means a circuit is a charging circuit or a discharging circuit. The direction of the flow of current is different for both the circuits.
In a charging circuit, where the battery is getting charged, the flow of positive charge is from positive to negative. However, in a discharging circuit, the flow of positive charge is from negative to positive.
As for the charging circuit, the flow of positive charge is from positive to negative and for the discharging circuit, the flow of positive charge is from negative to positive. So, we cannot be sure of it.

Therefore, the direction may be from positive to negative. So, option B is correct.

Note:
The fact that positive charge is moving is only a convention.
The only thing moving during a current flow is the electron. Since the flow of electrons from one side of the conductor to the other side decreases the negative charge density from one side we assume that all positive charge has moved to that part.
Practically proton motion does not take place.