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BLOCK 4Types of circuits series circuits 2nd eso - Contenido educativo

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Subido el 27 de febrero de 2023 por Beatriz T.

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BLOCK 4Types of circuits series circuits 2nd eso

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Lock 4. 00:00:00
Types of circuits. 00:00:01
Series and parallel. 00:00:03
Electricity. 00:00:06
Series circuits. 00:00:07
In these circuits, all the components are connected one after the other. 00:00:09
This way, all the current flows through all the load devices. 00:00:14
There is only one possible path for the electric current to flow through. 00:00:18
The same current flows through all the load devices. 00:00:23
If one load device stops working, none of them will work because the circuit will be open. 00:00:27
This happens when one of the load devices fails or is not connected to the circuit properly. 00:00:33
The energy supplied by the cell must be divided across all the load devices. 00:00:38
In the circuit in the drawing on the left, the energy is divided among the three lamps, 00:00:44
which all light up to the same level but do not shine as brightly as a single lamp would. 00:00:48
Parallel circuits. 00:00:54
In these circuits, the load devices are connected on different branches of the wire. 00:00:56
There are several possible paths for the electric current to flow through. 00:01:01
The electric current is split across all the possible paths 00:01:06
and more current will circulate through the branch that offers the least resistance. 00:01:09
The current intensity that flows through each load device is different. 00:01:14
Even if one of the load devices stops working, 00:01:18
the rest continue to work because the electric current takes another path, 00:01:21
the circuit is closed by another path. 00:01:25
The energy supplied by the cell reaches each branch of the circuit directly. 00:01:28
Therefore, all the lamps shine with the same brightness as a single lamp located on a single branch. 00:01:33
However, the cell will run down sooner. 00:01:39
Series-parallel combination circuits. 00:01:43
These circuits contain devices connected in series and in parallel. 00:01:46
In this case, the circuits have properties of both series circuits and parallel circuits. 00:01:51
Solving circuits. 00:01:57
To learn how to solve circuits, we generally begin with circuits composed only of cells and resistors. 00:01:59
The way that we put these resistors together is called the association of resistors. 00:02:05
This gives us the three types of basic circuits that we have just seen. 00:02:11
To calculate an unknown variable in a series, parallel or series-parallel combination circuit, 00:02:15
we add all the resistors together and replace them with a single one, which we call the total resistance. 00:02:21
This way, we make the circuit equivalent to a simple circuit with just one resistor. 00:02:28
With this simple circuit, we can apply Ohm's law to make our calculations quickly 00:02:33
and then calculate the values for each resistor. 00:02:38
The circuit formed with the equivalent resistors is called an equivalent circuit. 00:02:41
We can obtain two things from this circuit. 00:02:46
The currents flowing through the circuit. 00:02:50
The potential drops taking place across the components. 00:02:53
Solving series circuits. 00:02:57
To simplify things, we will solve a circuit formed by three resistors connected in series to a cell. 00:02:59
We will solve it in the same way that we would solve any circuit with resistors connected in series, 00:03:06
regardless of how many there are. 00:03:12
We calculate the equivalent resistance of a series circuit 00:03:15
by adding up the values of all the resistors in the circuit. 00:03:19
In this case, 00:03:23
Rt equals R1 plus R2 plus R3. 00:03:25
And the equivalent circuit is one with only one resistor with the equivalent resistance. 00:03:29
Since this circuit is equivalent to the last one, 00:03:36
the current flowing through the two circuits will be the same. 00:03:39
We apply Ohm's law to calculate the current flowing through the equivalent resistance. 00:03:43
Since the resistors are in series, 00:03:49
the current is the same in them all and it is equal to the total current of the circuit. 00:03:51
By contrast, the total voltage or potential difference supplied by the cell or power source 00:03:57
is divided across all the resistors. 00:04:03
We can calculate this with Ohm's law. 00:04:06
It must hold that all the energy supplied by the cell, Vt, 00:04:09
will be equal to the potential drop across each resistor. 00:04:13
Relationship between the variables of the real circuit and the equivalent circuit. 00:04:17
The equivalent resistance is equal to the sum of all resistances in the circuit. 00:04:23
The current flowing through all of the resistors in the circuit is the same 00:04:29
and is equal to the current of the equivalent circuit. 00:04:32
The total voltage delivered by the power source 00:04:36
is the sum of the potential drops across each of the resistors. 00:04:39
Worked example of a series circuit. 00:04:43
From the series circuit shown in the figure, 00:04:46
calculate the current flowing through each resistor and the potential drop across each one. 00:04:49
First, we calculate the equivalent resistance by adding up all the resistances. 00:04:54
The equivalent resistance is 500 Ohms. 00:05:00
This figure shows the resulting equivalent circuit. 00:05:04
We use Ohm's law to calculate the total current. 00:05:08
This gives us 20 mA. 00:05:11
Since this is a series circuit, 00:05:14
the total current of the circuit is the same current that flows across each of the resistors in the circuit. 00:05:16
To calculate the potential drops across each resistor, 00:05:22
we apply Ohm's law in each resistor using the current values that we just calculated. 00:05:25
We can check that we have done the exercise correctly by adding up the potential drops. 00:05:30
The result should be equal to the total voltage supplied by the cell that is 10 volts. 00:05:35
VT equals V1 plus V2 equals 4V plus 6V equals 10V. 00:05:41
Autor/es:
BEATRIZ TORREJON TEVAR
Subido por:
Beatriz T.
Licencia:
Reconocimiento - No comercial
Visualizaciones:
27
Fecha:
27 de febrero de 2023 - 17:55
Visibilidad:
Público
Centro:
IES CERVANTES
Duración:
05′ 48″
Relación de aspecto:
1.78:1
Resolución:
1280x720 píxeles
Tamaño:
75.75 MBytes

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