Define a series circuit .

A series circuit consists of two or more components connected end to end, forming a single loop.

Define a parallel circuit .

A parallel circuit consists of two or more components connected along separate branches of the circuit.

What happens to the current at each point in a series circuit?

The current is the same at all points in a series circuit.

How is the potential difference of the power supply shared in a series circuit?

The total potential difference of the power supply is shared between the components.

In a series circuit, the total resistance of two components is the ______ of the resistance of each component.

In a series circuit, the total resistance of two components is the sum of the resistance of each component.

How does the total current in a parallel circuit relate to the currents in the separate branches?

The total current is the sum of the currents through the separate branches, e.g. I = I ₁ + I ₂.

What is true about the potential difference across each component in a parallel circuit?

The potential difference across each component in a parallel circuit is the same.

True or False? In a parallel circuit, the current always splits equally between the branches.

False. The current only splits equally if the resistance of the components along each branch is identical.

What happens to the total resistance of a circuit as more resistors are added in series, and why?

The total resistance increases , because the charge has to pass through more resistors, causing a higher number of collisions.

How does the total resistance of resistors connected in parallel compare with the resistance of the smallest individual resistor?

The total resistance is less than the resistance of the smallest individual resistor.

Explain why connecting a resistor in parallel decreases the total resistance of a circuit.

Each extra resistor creates an additional pathway for the charge to flow through, so only some of the charge flows along each path, allowing more charge to flow overall and leading to a smaller overall resistance.

In a parallel circuit, each component can be controlled individually because each one has its own ______ .

In a parallel circuit, each component can be controlled individually because each one has its own switch .

What happens to the rest of a parallel circuit if one component stops working?

The other components continue to function normally.

True or False? Increasing the number of resistors in a series circuit decreases the total resistance.

False. It increases the total resistance, since the charge must pass through more resistors.

How does the current compare in series and parallel circuits?

In a series circuit, the current is the same at all points. In a parallel circuit, the current splits at junctions, with some going one way and the rest going the other.

How does the potential difference of the power supply compare in series and parallel circuits?

In a series circuit, the voltage is shared between the components. In a parallel circuit, the voltage across each component is the same.

How does connecting two identical resistors in series affect the total resistance, compared with a single resistor?

The total resistance is larger , because the charge has to push through multiple components, increasing the number of collisions.

How does connecting two identical resistors in parallel affect the total resistance, compared with a single resistor?

The total resistance is smaller , because the charge has more than one pathway to take, so only some charge flows along each path.

In the worked example, the components share the supply's potential difference, so 12 V – 8 V = ______ V.

In the worked example, the components share the supply's potential difference, so 12 V – 8 V = 4 V.

True or False? In a parallel circuit, the potential difference across each component is different.

False. The potential difference across each component in a parallel circuit is the same.

Define direct current (d.c.) .

Direct current is a current that is steady, constantly flowing in the same direction in a circuit, from positive to negative.

Define alternating current (a.c.) .

Alternating current is a current that continuously changes its direction, going back and forth around a circuit.

State two disadvantages of connecting components in series.

If one component breaks, all the others stop working . The components cannot be controlled (switched on and off) separately.

How is direct current represented differently from alternating current on an oscilloscope?

Direct current is shown as a flat, horizontal line. Alternating current is shown as a wave (sine curve).

The potential difference between the terminals of an a.c. supply varies as a ______ curve.

The potential difference between the terminals of an a.c. supply varies as a sine curve.

What is meant by the frequency of an alternating current?

The number of times the current changes direction back and forth each second .

True or False? A d.c. power supply has two identical terminals.

False. A d.c. power supply has a fixed positive terminal and a fixed negative terminal; it is an a.c. supply that has two identical terminals.

State the frequency and potential difference of mains electricity in the UK.

50 Hz and a potential difference of about 230 V .

Define mains electricity .

Mains electricity is the electricity generated by power stations and transported around the country through the National Grid.

What type of current is mains electricity, and what are its frequency and potential difference in the UK?

Mains electricity is an alternating current (a.c.) supply, with a frequency of 50 Hz and a potential difference of about 230 V .

What three wires make up a three-core cable?

A live wire, a neutral wire and an earth wire.

In a three-core cable, the live wire's insulation is coloured ______ , while the neutral wire's is blue.

In a three-core cable, the live wire's insulation is coloured brown , while the neutral wire's is blue.

Define the live wire .

The live wire carries the alternating potential difference from the mains supply to a circuit.

What is the function of the neutral wire?

The neutral wire forms the opposite end of the circuit to the live wire, completing the circuit.

What is the function of the earth wire?

The earth wire acts as a safety wire, preventing the appliance from becoming live and reducing the risk of electric shocks if the appliance malfunctions.

True or False? The neutral wire is the most dangerous of the three wires in a mains cable.

False. The live wire is the most dangerous, as it can cause electrocution if touched without the earth wire; the neutral wire is much less dangerous due to its lower voltage.

What are the typical potential differences of the live, neutral and earth wires?

Live ≈ 230 V; neutral close to 0 V; earth 0 V.

Why does the earth wire normally have a potential difference of 0 V?

Under normal circumstances, the earth wire does not carry any electricity - it is there for safety only.

Describe how the earth wire and fuse work together to protect a person if the live wire touches an appliance's metal casing.

The earth wire provides a low-resistance path to the earth, causing a surge of current in the earth and live wires. This surge passes through the fuse, melting it and breaking the circuit, which cuts off the electricity supply to the appliance.

The neutral wire is much safer than the live wire, although it can still deliver a ______ shock.

The neutral wire is much safer than the live wire, although it can still deliver a small shock.

Why do electricians switch off the mains supply before working on electrical appliances?

Because they may come into contact with live wires. As there is a large potential difference between the live wire (230 V) and the electrician (0 V), a current would pass through the electrician's body to reach the earth.

True or False? If an appliance is switched off, the live wire cannot cause an electric shock, even if the mains supply is still on.

False. Even if a device is switched off, if the mains supply is on, the live wire can still cause an electric shock.

What can happen if a person provides a connection between the live wire and earth, and why?

A large current can pass through them, providing a potentially lethal shock, because of the large potential difference between the live wire (230 V) and the earth (0 V).

GCSEPhysicsAQAFlashcardsElectricitySeries & Parallel Circuits

Series & Parallel Circuits (AQA GCSE Physics): Flashcards

Exam code: 8463

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FrontSeries & Parallel Circuits
Define a series circuit.

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Cards in this collection (44)

Define a series circuit.
A series circuit consists of two or more components connected end to end, forming a single loop.
Define a parallel circuit.
A parallel circuit consists of two or more components connected along separate branches of the circuit.
What happens to the current at each point in a series circuit?
The current is the same at all points in a series circuit.
How is the potential difference of the power supply shared in a series circuit?
The total potential difference of the power supply is shared between the components.
In a series circuit, the total resistance of two components is the ______ of the resistance of each component.
In a series circuit, the total resistance of two components is the sum of the resistance of each component.
How does the total current in a parallel circuit relate to the currents in the separate branches?
The total current is the sum of the currents through the separate branches, e.g. I = I₁ + I₂.
What is true about the potential difference across each component in a parallel circuit?
The potential difference across each component in a parallel circuit is the same.
True or False?
In a parallel circuit, the current always splits equally between the branches.
False.
The current only splits equally if the resistance of the components along each branch is identical.
Define combined resistance for resistors connected in series.
The combined resistance of resistors in series is the sum of their individual resistances:
$R = R_{1} + R_{2} + R_{3} . . .$
What happens to the total resistance of a circuit as more resistors are added in series, and why?
The total resistance increases, because the charge has to pass through more resistors, causing a higher number of collisions.
How does the total resistance of resistors connected in parallel compare with the resistance of the smallest individual resistor?
The total resistance is less than the resistance of the smallest individual resistor.
Explain why connecting a resistor in parallel decreases the total resistance of a circuit.
Each extra resistor creates an additional pathway for the charge to flow through, so only some of the charge flows along each path, allowing more charge to flow overall and leading to a smaller overall resistance.
In a parallel circuit, each component can be controlled individually because each one has its own ______.
In a parallel circuit, each component can be controlled individually because each one has its own switch.
What happens to the rest of a parallel circuit if one component stops working?
The other components continue to function normally.
True or False?
Increasing the number of resistors in a series circuit decreases the total resistance.
False.
It increases the total resistance, since the charge must pass through more resistors.
How does the current compare in series and parallel circuits?
In a series circuit, the current is the same at all points. In a parallel circuit, the current splits at junctions, with some going one way and the rest going the other.
How does the potential difference of the power supply compare in series and parallel circuits?
In a series circuit, the voltage is shared between the components. In a parallel circuit, the voltage across each component is the same.
How does connecting two identical resistors in series affect the total resistance, compared with a single resistor?
The total resistance is larger, because the charge has to push through multiple components, increasing the number of collisions.
How does connecting two identical resistors in parallel affect the total resistance, compared with a single resistor?
The total resistance is smaller, because the charge has more than one pathway to take, so only some charge flows along each path.
In the worked example, the components share the supply's potential difference, so 12 V – 8 V = ______ V.
In the worked example, the components share the supply's potential difference, so 12 V – 8 V = 4 V.
True or False?
In a parallel circuit, the potential difference across each component is different.
False.
The potential difference across each component in a parallel circuit is the same.
Define direct current (d.c.).
Direct current is a current that is steady, constantly flowing in the same direction in a circuit, from positive to negative.
Define alternating current (a.c.).
Alternating current is a current that continuously changes its direction, going back and forth around a circuit.
State two disadvantages of connecting components in series.
If one component breaks, all the others stop working. The components cannot be controlled (switched on and off) separately.
How is direct current represented differently from alternating current on an oscilloscope?
Direct current is shown as a flat, horizontal line. Alternating current is shown as a wave (sine curve).
The potential difference between the terminals of an a.c. supply varies as a ______ curve.
The potential difference between the terminals of an a.c. supply varies as a sine curve.
What is meant by the frequency of an alternating current?
The number of times the current changes direction back and forth each second.
True or False?
A d.c. power supply has two identical terminals.
False.
A d.c. power supply has a fixed positive terminal and a fixed negative terminal; it is an a.c. supply that has two identical terminals.
State the frequency and potential difference of mains electricity in the UK.
50 Hz and a potential difference of about 230 V.
Define mains electricity.
Mains electricity is the electricity generated by power stations and transported around the country through the National Grid.
What type of current is mains electricity, and what are its frequency and potential difference in the UK?
Mains electricity is an alternating current (a.c.) supply, with a frequency of 50 Hz and a potential difference of about 230 V.
What three wires make up a three-core cable?
A live wire, a neutral wire and an earth wire.
In a three-core cable, the live wire's insulation is coloured ______, while the neutral wire's is blue.
In a three-core cable, the live wire's insulation is coloured brown, while the neutral wire's is blue.
Define the live wire.
The live wire carries the alternating potential difference from the mains supply to a circuit.
What is the function of the neutral wire?
The neutral wire forms the opposite end of the circuit to the live wire, completing the circuit.
What is the function of the earth wire?
The earth wire acts as a safety wire, preventing the appliance from becoming live and reducing the risk of electric shocks if the appliance malfunctions.
True or False?
The neutral wire is the most dangerous of the three wires in a mains cable.
False.
The live wire is the most dangerous, as it can cause electrocution if touched without the earth wire; the neutral wire is much less dangerous due to its lower voltage.
What are the typical potential differences of the live, neutral and earth wires?
Live ≈ 230 V; neutral close to 0 V; earth 0 V.
Why does the earth wire normally have a potential difference of 0 V?
Under normal circumstances, the earth wire does not carry any electricity - it is there for safety only.
Describe how the earth wire and fuse work together to protect a person if the live wire touches an appliance's metal casing.
The earth wire provides a low-resistance path to the earth, causing a surge of current in the earth and live wires. This surge passes through the fuse, melting it and breaking the circuit, which cuts off the electricity supply to the appliance.
The neutral wire is much safer than the live wire, although it can still deliver a ______ shock.
The neutral wire is much safer than the live wire, although it can still deliver a small shock.
Why do electricians switch off the mains supply before working on electrical appliances?
Because they may come into contact with live wires. As there is a large potential difference between the live wire (230 V) and the electrician (0 V), a current would pass through the electrician's body to reach the earth.
True or False?
If an appliance is switched off, the live wire cannot cause an electric shock, even if the mains supply is still on.
False.
Even if a device is switched off, if the mains supply is on, the live wire can still cause an electric shock.
What can happen if a person provides a connection between the live wire and earth, and why?
A large current can pass through them, providing a potentially lethal shock, because of the large potential difference between the live wire (230 V) and the earth (0 V).

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