Series and Parallel Circuits | Electricity | Physics | FuseSchool

Summary

This script explains the basics of electrical circuits, focusing on series and parallel configurations. It describes how components are connected and the flow of current in each. The script also covers voltage, measured in volts, and how it represents the energy push from a battery. It introduces the use of voltmeters and ammeters, explaining their connection methods. The concept of resistance, measured in ohms, is explored, along with how it affects current flow. The script concludes with calculations for total voltage, current, and resistance in both series and parallel circuits, providing examples to illustrate the principles.

Takeaways

• 🔌 There are two main types of electrical circuits: series and parallel.
• 🔄 In a series circuit, components are connected end-to-end, creating a single path for current flow.
• 🔄 In a parallel circuit, components are connected side-by-side, allowing current to divide and flow in multiple paths.
• 🔋 Voltage is the electrical push provided by a battery, measured in joules per coulomb (volts).
• 🔌 Voltmeters measure voltage and are always connected in parallel to the circuit.
• 💧 Current is the flow of negatively charged electrons in a circuit, analogous to water flowing in a pipe.
• 📏 Resistance is the opposition to current flow, measured in ohms (symbolized by the Greek letter omega).
• 🔗 In series circuits, the total voltage is shared among components, with the same current flowing through each.
• 🔗 In parallel circuits, the voltage across each component is the same, but the total current is the sum of the individual currents.
• 🔢 The total resistance in a series circuit is the sum of the individual resistances.
• 🔢 The total resistance in a parallel circuit is less than the smallest individual resistance, calculated using specific formulas.
• 📘 The script provides examples of calculating voltage, current, and resistance in both series and parallel circuits.

Q & A

What are the two main types of electrical circuits?

The two main types of electrical circuits are series and parallel circuits.

How are components connected in a series circuit?

In a series circuit, components are connected end to end, one after the other, forming a simple loop for the current to flow round.

What is the difference between a series and a parallel circuit?

In a series circuit, components are connected end to end with a single path for current flow, whereas in a parallel circuit, components are connected side by side allowing the current to divide and flow in multiple paths.

What is voltage and how is it measured?

Voltage is a measure of the electrical push that the battery gives to the electrons, representing the energy in joules given to each packet of electrons. It is measured in volts using a voltmeter.

How should a voltmeter be connected in a circuit?

A voltmeter should always be connected in parallel when added to a circuit to measure the voltage across a component.

What is the relationship between current, coulombs, and amps?

Electric current is the flow of negatively charged electrons, measured in coulombs per second, which is equivalent to amps.

How is an ammeter connected in a circuit?

An ammeter must be connected in series with the circuit to measure the current flowing through it.

What is resistance and how is it measured?

Resistance is a measure of the opposition to current flow in an electrical circuit and is measured in ohms, symbolized by the Greek letter omega.

How does the total voltage in a series circuit relate to individual components?

In a series circuit, the total voltage or potential difference of the power supply is shared between the components, with the same current flowing through each component.

What is the formula for calculating total resistance when resistors are in parallel?

When resistors are in parallel, the total resistance (R) can be calculated using the formula: 1/R = 1/R1 + 1/R2, where R1 and R2 are the resistances of the individual components.

How does the total current in a parallel circuit compare to the currents through individual components?

In a parallel circuit, the total current through the whole circuit is the sum of the currents through the separate components.

If each cell provides a potential difference of 1.5 volts, what is the total potential difference provided by four cells in a circuit?

The total potential difference provided by four cells in a circuit would be 4 times 1.5 volts, which equals 6 volts.

If the current through a lamp is 0.20 amps and through a resistor is 0.10 amps, what would be the reading on the ammeter in a parallel circuit?

In a parallel circuit, the reading on the ammeter would be the sum of the currents through the lamp and the resistor, which is 0.20 amps + 0.10 amps = 0.30 amps.

Outlines

00:00

🔌 Basic Electrical Circuits

This paragraph introduces the two fundamental types of electrical circuits: series and parallel. In a series circuit, components are connected end-to-end, creating a single path for the current to flow. In contrast, a parallel circuit has components connected side by side, allowing the current to split and flow in multiple directions. The paragraph also explains the concept of voltage, which is the electrical force provided by a battery, measured in volts (joules per coulomb). A voltmeter is used to measure this voltage and is connected in parallel to the circuit. The script also discusses the measurement of electric current, which is the flow of negatively charged electrons, measured in coulombs per second or amps, using an ammeter connected in series.

🔋 Understanding Voltage and Current

The script continues by explaining the role of voltage as the force that pushes electrons around a circuit and resistance as the opposition to the flow of current, measured in ohms. It uses the analogy of water flow in a pipe to help understand the concept of current. The paragraph also covers how voltage and current are distributed in series and parallel circuits. In a series circuit, the total voltage is shared among the components, with the same current flowing through each. The total resistance is the sum of individual resistances. In a parallel circuit, the voltage across each component is the same, but the total current is the sum of the currents through each component, and the total resistance is less than that of the smallest individual resistor.

🔍 Calculating Resistance in Series and Parallel Circuits

This section of the script provides practical examples of calculating the total resistance in both series and parallel circuits. For series circuits, the total resistance is simply the sum of the individual resistances. However, for parallel circuits, a specific formula is used to calculate the total resistance, which results in a lower value than any individual resistor. The script includes a practical example where two resistors of 3 ohms each in parallel result in a total resistance of 1.5 ohms. Another example is given where resistors of 10 ohms and 5 ohms in parallel result in a total resistance of approximately 3.33 ohms. The paragraph concludes by encouraging the viewer to apply these rules to understand how series and parallel circuits differ and how resistance can be calculated experimentally.

Keywords

💡Series Circuit

A series circuit is one where the components are connected end to end, creating a single path for the electric current to flow. This means that the current passing through each component is the same. In the video, the concept is used to explain the behavior of current in a simple loop, emphasizing that the total resistance in a series circuit is the sum of the individual resistances of its components.

💡Parallel Circuit

A parallel circuit is where components are connected side by side, allowing the current to divide and flow in multiple paths. The video uses this concept to illustrate how current分流, with some going one way and the rest another, resulting in the same voltage across each component. The total resistance in a parallel circuit is less than that of the smallest individual resistor.

💡Voltage

Voltage is described as the electrical 'push' that a battery gives to electrons, measured in joules per coulomb or volts. It represents the energy given to each packet of electrons. The video explains that voltmeters, which measure voltage, are always connected in parallel to a circuit, and it uses the example of a voltmeter measuring the voltage across a lamp.

💡Current

Current is the flow of negatively charged electrons through a wire, analogous to water flowing in a pipe but with electric charge instead. The video defines electric current as coulombs per second or amps and explains that an ammeter, which measures current, must be connected in series. It uses the example of measuring the current flowing through a lamp and a resistor.

💡Resistance

Resistance is the opposition to current flow in an electrical circuit, measured in ohms, symbolized by the Greek letter omega (Ω). The video explains that higher resistance makes it more difficult for current to flow, likening it to a narrowing pipe that restricts the flow of water. It also discusses how resistance is calculated in series and parallel circuits.

💡Ohm's Law

Though not explicitly mentioned by name, Ohm's Law is implied in the discussion of resistance, current, and voltage. It states that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance between them. The video uses this principle to explain how voltage is shared among components in a series circuit and how current is divided in a parallel circuit.

💡Ammeter

An ammeter is a device used to measure the electric current in a circuit. The video explains that it must be connected in series with the circuit to measure the current accurately. It uses the ammeter to measure the current flowing through a lamp and a resistor, showing how to calculate the total current in a circuit.

💡Voltmeter

A voltmeter is used to measure the voltage across two points in an electrical circuit. The video explains that it is always connected in parallel to the circuit and uses the example of measuring the voltage across a lamp to illustrate this concept.

💡Coulombs

Coulombs are the unit of electric charge, analogous to the amount of water in a bucket. The video uses coulombs to explain the measurement of electric current, which is coulombs per second or amps, providing a tangible way to understand the flow of electric charge.

💡Joules

Joules are the unit of energy, and in the context of the video, they are used to explain voltage as joules per coulomb. This helps to convey the concept of voltage as a measure of energy given to electrons, which is crucial for understanding how electrical circuits work.

💡Potential Difference

Potential difference, synonymous with voltage, is the difference in electric potential between two points in an electric circuit. The video uses the term to explain how the total voltage from a power supply is shared among components in a series circuit or remains the same across each component in a parallel circuit.

Highlights

There are two main types of electrical circuits: series and parallel.

In a series circuit, components are connected end to end, forming a loop for current flow.

In a parallel circuit, components are connected side by side, dividing the current flow.

Voltage is the electrical push given by the battery, measured in joules per coulomb or volts.

A voltmeter measures voltage and is always connected in parallel to a circuit.

Electric current represents the flow of negatively charged electrons, measured in coulombs per second or amps.

An ammeter is used to measure current and must be connected in series.

Resistance measures the opposition to current flow and is measured in ohms.

For series circuits, the total voltage is shared between components, with the same current through each.

In series circuits, the total resistance is the sum of individual resistances.

In parallel circuits, the voltage across each component is the same.

The total current in a parallel circuit is the sum of the currents through separate components.

The total resistance in a parallel circuit is less than the smallest individual resistor.

The potential difference provided by four cells in a circuit can be calculated by multiplying the voltage of one cell by four.

The voltmeter reading depends on the circuit configuration and the voltage across the lamp.

The ammeter reading is the sum of the currents through the lamp and the resistor.

Resistors in parallel have a combined resistance calculated using the formula 1/R = 1/R1 + 1/R2.

The total resistance in a parallel circuit is lower than each individual resistor.

Understanding series and parallel circuits is crucial for calculating resistance experimentally.

Transcripts

there are two main types of electrical

circuit

series and parallel

in a series circuit the components are

connected end to end

one after the other

they make a simple loop for the current

to flow round

in a parallel circuit the components are

connected side by side so the current

divides some going one way and the rest

the other way

here's an example of two circuits both

containing a cell and two bulbs

one circuit is series the other is

parallel the voltage is a measure of the

electrical push that the battery gives

to the electrons

it's a measure of the energy in joules

given to each packet of electrons

coulombs

so the voltmeter measures joules per

coulomb or volts

voltmeters are always connected in

parallel when added to a circuit

in this diagram the voltmeter is

measuring the voltage across the lamp

[Music]

we can also measure the current flowing

through a circuit

in a wire the current is the flow of

negatively charged electrons

we can imagine it being like water

flowing in a pipe but instead of water

it's a flow of electric charge which we

measure in coulombs

so electric current is coulombs per

second or amps measured using an ammeter

which must be connected in series

resistance is a measure of the

opposition to current flow in an

electrical circuit

resistance is measured in ohms

symbolized by the greek letter

omega the higher the resistance the more

difficult it is for a current to flow

a good way to think about electricity is

voltage as the force pushing the current

around

and resistance is as if the pipe

carrying the current narrows

[Music]

for components connected in series the

total voltage or potential difference of

the power supply is shared between the

components

there is the same current through each

component

the total resistance of two components

is the sum of the resistance of each

component

for components connected in parallel the

voltage or potential difference across

each component is the same

the total current through the whole

circuit is the sum of the currents

through the separate components

and the total resistance of two

resistors is less than the resistance of

the smallest individual resistor

let's have a go at applying some of

those rules

each cell provides a potential

difference of 1.5 volts

what's the potential difference provided

by the four cells in the circuit

what will be the reading on the

voltmeter

the current through the lamp is 0.20

amps

the current through the resistor is 0.10

amps

what is the reading on the ammeter

pause the video while you work out the

answers

when resistors are in parallel things

work out a bit different

look at this circuit

if these two resistors were in series

then their combined value would be 3

ohms plus 3 ohms equals 6 ohms

but when in parallel we use this formula

in this example we have

if one over r equals two over three then

r equals three over two equals one point

five ohms the total resistance is lower

than each individual resistor

try this one

1 over r equals 1 over 10 plus 1 over 5

which equals three over ten

so r is ten over three which equals

three point three three ohms

how did you do

so now you know how series and parallel

circuits differ and how we can calculate

the resistance experimentally