Electric Circuits and Current Types

The flow of charge that powers devices.
Can be generated in two main ways:
- Converting chemical energy to electrical energy (e.g., batteries).
- Using a dynamo or generator, converting mechanical energy to electrical energy.
Batteries store chemical energy and release it as electricity.
- The term "volt" is introduced.
Dynamos (e.g., in bicycles or cars) use mechanical motion to generate electricity.
- Uses a turbine to generate electricity.

Obtained from electrochemical cells, which convert chemical energy into electrical energy.

Obtained from electric generators or dynamos, which convert mechanical energy into electrical energy.

Different applications and characteristics.
Direct Current (DC) is often abbreviated as "DC".
A battery is a source of direct current.
Batteries have a specific voltage (e.g., 1.5 volts) and amperage.
The amount of current from a battery is relatively constant and predictable.
If you have 4 batteries each 1 volt and they are connected as described it is known that the total voltage is 4 volts.

Can be transmitted over long distances, such as from power generation plants.
The direction of current flow is important.
Batteries have positive and negative terminals.
Current flows from the positive terminal to the negative terminal in a DC circuit.
Emphasizes the importance of the direction of current flow in DC circuits.
Closing the circuit allows current to flow and light the bulb.

DC is suitable for small circuits but cannot be easily transmitted over long distances due to resistance.
AC can be transmitted at high voltages over long distances from power stations.
DC is used in operating machines such as lamps and in electroplating.
- Electroplating involves using a solution with ions (e.g., silver ions) to coat objects.
- A direct current is passed through the solution, causing ions to move from a silver plate to the object being coated.
Direct current flows in one direction (from positive to negative).
Direct current cannot be easily transformed into higher voltages, unlike alternating current.
Transformers can convert high-voltage AC to lower voltages (e.g., from 220 volts to 5 volts for charging a mobile phone).
Mobile phones typically require a 5-volt DC supply.
Using a charger with a transformer is necessary to convert AC to DC for charging phones.
A graph of current vs. time shows that direct current remains constant, while alternating current varies.

Batteries are connected one after the other.
The negative terminal of one battery is connected to the positive terminal of the next.
Closing the switch allows current flow in a specific direction.
Each battery is placed behind the other in a series.

All positive terminals are connected together, and all negative terminals are connected together.
A wire connects all the positive terminals, and another wire connects all the negative terminals.
When the switch is closed, the connection allows current to flow.

Series connections provide higher voltage, while parallel connections provide higher current.
Series: batteries connected end-to-end.
Parallel: all positive terminals connected and all negative terminals connected.
In series, the negative of one cell connects to the positive of the next.
In parallel, all positives are connected, and all negatives are connected.

If each cell is 1.5 volts, connecting multiple cells in series increases the total voltage.
Connecting in series sums the voltages.
- $V{total} = V1 + V2 + V3 + …$
- If you connect 4 batteries that are each 1.5 volts in the manner as explained it yields 6 volts.
In parallel, the voltage remains the same as a single cell.
- Connecting batteries in parallel keeps the voltage the same as one of the batteries.
If there are four battery but you only get one of the voltage, this means that the batteries are connected in parallel.
In series connection, the total EMF (electromotive force) or voltage is the sum of individual EMFs/voltages.
- $E{total} = E1 + E2 + E3$
However EMF in parallel is using one battery.
Discusses an experiment of connecting lemons to light a lamp by comparing what would happen in both series and parallel.

How to get 3 volts from 3 batteries.
Connection to create 3 voltage is putting two in parallel and the other in series, where two parallel is considered as a single battery.
If you link one with series with 1.5 volts then the other is combined to get the value.
How to get 4.5 volts: use all the connections in series.
If there are six battery which has EMF of 1.5 what connections are best.
What if there are 6 volts and you want to connect the batteries to 6 voltage what connection would be best.
To get 6 divide by 1.5 volts and you get a value of 4
Then one connection becomes 1.5 , the other connection is 3 and subsequently 4.5 with the final being the 6 volts.
Put two batteries in parallel to get 3 connected with series.