Question

Which of the following statements is true about the flow of electrons in an electric circuit?
A. Electrons always flow from lower to higher potential.
B. Electrons always flow from higher to lower potential.
C. Electrons flow from lower to higher potential except through the power source.
D. Electrons flow from higher to lower potential except through the power source.

Answer 1

Hint: The electric current is the flow of charge inside a wire. Due to electricity, we are able to run many appliances which play very important roles in our daily life. To run the appliances, we need electricity, which can be drawn from a source. The source can be a battery or a generator.

Complete step by step answer:
The flow of charge is called electric current. But it’s very important to note that the direction of current is opposite of the direction of flow of electrons. This is because every charge wants to minimize its potential energy.
In a wire connected to a source, the wire acts as a conductor across which potential difference is applied. This potential difference creates an electric field inside the wire which accelerates the electrons and hence the electricity is generated.
For a positive charge, if we move from a region of high potential to lower potential, then its potential energy decreases. But in case of a negative charge or electrons, when we move from lower potential to higher potential, its potential energy decreases. Hence this process is feasible. This is the reason why electrons flow from negative to positive terminal or lower to higher potential.
But in case of power source, it travels from positive to negative terminal i.e. from higher to lower potential because it provides the closed path to the flow of charges so that electricity could flow.

Note:
While accounting potential energy, we have to include the sign also because all charges want to be stable and stability means even lesser energy. Means if potential energy is positive, charges want to get separated (like in case of like charges) but if charges are unlike, then the potential energy is negative and they want to come closer so that even more energy could be released.