Sources of Direct Current Quiz

Study Notes

Sources of Direct Current

Direct current (DC) is a unidirectional flow of electric charge.
Sources of DC include various types of cells and batteries.
These sources create a potential difference that drives the flow of electrons.
Different sources provide different levels of voltage and current.
The source must maintain a consistent potential difference for a constant DC.

Kinds of Cells

Primary cells are non-rechargeable. Once the chemical reactants are used up, the cell is spent.
- Examples: zinc-carbon cells, alkaline cells.
Secondary cells (batteries) are rechargeable. The chemical reactions are reversible and can be restored to their initial state.
- Examples: lead-acid batteries, nickel-cadmium (NiCd) batteries, lithium-ion batteries
- Rechargeable batteries store chemical energy and convert it to electrical energy. They have a longer lifespan than primary cells.

Electric Current As Rate of Flow of Electric Charge

Electric current is the rate at which electric charge flows through a conductor.
It is measured in amperes (A), where 1 ampere is equal to 1 coulomb of charge per second.
Mathematically, current (I) = charge (Q) / time (t).
Current represents the number of electrons flowing per unit time.

Direction of Current

Conventional current direction is defined as the direction in which positive charge would flow.
- Historically, positive charge was thought to be the carrier. This standard is still used.
Electron flow is the actual movement of negatively charged electrons.
- Electrons flow in the opposite direction to the conventional current.
- The direction of electron flow is against the direction of conventional current.
Both conventional and electron flow concepts are valid, and the choice depends on the context.

Description

Test your knowledge on the sources of direct current and the types of cells that produce it. This quiz covers the fundamentals of DC flow, primary and secondary cells, and their characteristics. Challenge yourself and learn more about electric current and its role in electrical devices.