Define electrical power .

Electrical power is defined as the rate at which energy is transferred or converted per unit of time, typically measured in watts (W).

What two quantities does electrical power depend upon?

The two quantities that electrical power depends on are the voltage and current of a device.

True or False? The unit of power is joules (J).

False. The unit of power is watts (W), where 1 watt is equivalent to 1 joule per second.

True or False? The unit watts (W) is the equivalent of joules per second (J/s).

True. The unit watts (W) is the equivalent to joules per second (J/s).

Describe the purpose of an electrical fuse .

An electrical fuse is a safety device designed to cut off the flow of electricity to an appliance if the current becomes too large (due to a fault or surge).

What happens to the wire in a fuse when the current becomes too large ?

If the current inside the wire becomes too large it heats up and melts .

State the three fuse sizes.

The three fuse sizes are 3 A, 5 A and 13 A.

State the correct fuse size for an appliance that requires a current of 4.5 A.

The correct fuse size for an appliance that requires a current of 4.5 A is 5 A .

True or False? Power is the rate of doing work.

True. Power is defined as the rate of doing work, or, the rate of energy transfer. It is measured in watts (W).

How is energy transferred related to work done in an electrical circuit?

Work done is equal to the energy transferred in an electrical circuit.

True or False? Work is done when energy is transferred by moving charges in a circuit.

True. Work is done when energy is transferred by moving charges in a circuit.

True or False? The energy supplied by the battery is equal to the energy transferred only to the wires of an electrical circuit with several components.

False. The energy supplied by the battery is equal to the energy transferred to all the components in an electrical circuit.

True or False? Mains electricity is potentially lethal.

True. Mains electricity is potentially lethal.

What is the definition of an electrical safety hazard ?

An electrical safety hazard is a condition that poses a risk of electric shock or fire, such as damaged insulation or overheating cables .

What hazards do damp conditions pose to electrical circuits or appliances?

Hazards that damp conditions pose to electrical circuits or appliances are that the moisture can conduct electricity, causing a short circuit or posing an electrocution risk .

Define the term double insulation .

Double insulation is when an appliance has insulation around the wires and a non-metallic case, eliminating the need for an earth wire.

Earthing is an electrical safety feature found in appliances with metal cases that provides a low resistance path to the earth to prevent electric shocks.

True or False? A fuse is an example of an electrical safety feature built into domestic appliances.

True. A fuse is an example of an electrical safety feature built into domestic appliances.

What is the purpose of the earth wire in an electrical appliance?

The purpose of the earth wire in an electrical appliance is to provide a low-resistance path to the Earth for the current.

What is the role of circuit breakers in a house?

The role of circuit breakers in a house is to quickly shut off electricity if the current exceeds a certain value, protecting the electrical system.

Which materials are commonly used to insulate wires ?

The materials commonly used to insulate wires are rubber and plastic .

How do electrical cables overheat ?

Electrical cables overheat when too much current passes through the wire. This can potentially cause a fire or melt the insulation.

What do the electrons flowing in the wires around a circuit collide with?

The electrons flowing in the wires around a circuit collide with the metal ions .

State why the temperature of an electrical resistor increases.

The temperature of an electrical resistor increases because of the collisions between the electrons flowing in the conductor and the lattice of metal ions within the conductor.

True or False? When current flows through an electrical wire some energy is dissipated to the surroundings by heating .

True. When current flows through an electrical wire, some energy is dissipated to the surroundings by heating .

State a domestic example of when the heating effect of an electrical wire is utilised.

A domestic example of when the heating effect of an electrical wire is utilised can be any one from: Electric heaters Electric ovens Electric hobs Toasters Kettles Filament bulbs Fuses

State the type of current supplied by mains electricity .

Mains electricity supplies an alternating current (a.c.).

What device supplies a direct current (d.c.) to an electrical circuit?

A battery or cell supplies a direct current to an electrical circuit.

Define direct current .

Direct current is a steady current, constantly flowing in one direction through a circuit, from positive to negative.

True or False? The potential difference across a cell in a d.c. circuit travels in two directions only.

False . The potential difference across a cell in a d.c. circuit travels in one direction only.

Define an alternating current (a.c.).

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

True or False? An alternating current power supply has two different terminals, one positive and one negative.

False . An alternating current power supply has two identical terminals that change from positive to negative and back again.

State the frequency of mains electricity in the UK.

The frequency of mains electricity in the UK is 50 Hz .

State the type of current used by a lamp plugged into a domestic plug socket.

Alternating current is used by a lamp plugged into a domestic plug socket.

IGCSEPhysicsEdexcelFlashcards2. ElectricityElectrical Power & Mains Electricity

Electrical Power & Mains Electricity (Edexcel IGCSE Physics)

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FrontElectrical Power & Fuses
Define electrical power.
FrontElectrical Power & Fuses
State the electrical power equation
BackElectrical Power & Fuses
The electrical power equation is: $P = I \times V$
Where:
$P$ = power, measured in watts (W)
$V$ = voltage, measured in volts (V)
$I$ = current, measured in amperes (A)

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Cards in this collection (39)

Define electrical power.
Electrical power is defined as the rate at which energy is transferred or converted per unit of time, typically measured in watts (W).
What two quantities does electrical power depend upon?
The two quantities that electrical power depends on are the voltage and current of a device.
State the electrical power equation
The electrical power equation is: $P = I \times V$
Where:
- $P$ = power, measured in watts (W)
- $V$ = voltage, measured in volts (V)
- $I$ = current, measured in amperes (A)
True or False?
The unit of power is joules (J).
False.
The unit of power is watts (W), where 1 watt is equivalent to 1 joule per second.
True or False?
The unit watts (W) is the equivalent of joules per second (J/s).
True.
The unit watts (W) is the equivalent to joules per second (J/s).
Describe the purpose of an electrical fuse.
An electrical fuse is a safety device designed to cut off the flow of electricity to an appliance if the current becomes too large (due to a fault or surge).
What happens to the wire in a fuse when the current becomes too large?
If the current inside the wire becomes too large it heats up and melts.
Draw the electrical symbol for a fuse.
The electrical symbol for a fuse looks like this:
State the three fuse sizes.
The three fuse sizes are 3 A, 5 A and 13 A.
State the correct fuse size for an appliance that requires a current of 4.5 A.
The correct fuse size for an appliance that requires a current of 4.5 A is 5 A.
True or False?
Power is the rate of doing work.
True.
Power is defined as the rate of doing work, or, the rate of energy transfer.
It is measured in watts (W).
How is energy transferred related to work done in an electrical circuit?
Work done is equal to the energy transferred in an electrical circuit.
True or False?
Work is done when energy is transferred by moving charges in a circuit.
True.
Work is done when energy is transferred by moving charges in a circuit.
True or False?
The energy supplied by the battery is equal to the energy transferred only to the wires of an electrical circuit with several components.
False.
The energy supplied by the battery is equal to the energy transferred to all the components in an electrical circuit.
What is the equation for calculating energy transfers in terms of current, potential difference and time?
The equation for calculating energy transfers in terms of current, potential difference and time is: $E = I \times V \times t$
Where:
- $E$ = energy transferred, measured in joules (J)
- $I$ = current, measured in amperes (A)
- $V$ = potential difference, measured in volts (V)
- $t$ = time, measured in seconds (s)
True or False?
Mains electricity is potentially lethal.
True.
Mains electricity is potentially lethal.
What is the definition of an electrical safety hazard?
An electrical safety hazard is a condition that poses a risk of electric shock or fire, such as damaged insulation or overheating cables.
What hazards do damp conditions pose to electrical circuits or appliances?
Hazards that damp conditions pose to electrical circuits or appliances are that the moisture can conduct electricity, causing a short circuit or posing an electrocution risk.
Define the term double insulation.
Double insulation is when an appliance has insulation around the wires and a non-metallic case, eliminating the need for an earth wire.
Define earthing.
Earthing is an electrical safety feature found in appliances with metal cases that provides a low resistance path to the earth to prevent electric shocks.
True or False?
A fuse is an example of an electrical safety feature built into domestic appliances.
True.
A fuse is an example of an electrical safety feature built into domestic appliances.
What is the purpose of the earth wire in an electrical appliance?
The purpose of the earth wire in an electrical appliance is to provide a low-resistance path to the Earth for the current.
What is the role of circuit breakers in a house?
The role of circuit breakers in a house is to quickly shut off electricity if the current exceeds a certain value, protecting the electrical system.
Which materials are commonly used to insulate wires?
The materials commonly used to insulate wires are rubber and plastic.
How do electrical cables overheat?
Electrical cables overheat when too much current passes through the wire. This can potentially cause a fire or melt the insulation.
What do the electrons flowing in the wires around a circuit collide with?
The electrons flowing in the wires around a circuit collide with the metal ions.
State why the temperature of an electrical resistor increases.
The temperature of an electrical resistor increases because of the collisions between the electrons flowing in the conductor and the lattice of metal ions within the conductor.
True or False?
When current flows through an electrical wire some energy is dissipated to the surroundings by heating.
True.
When current flows through an electrical wire, some energy is dissipated to the surroundings by heating.
State a domestic example of when the heating effect of an electrical wire is utilised.
A domestic example of when the heating effect of an electrical wire is utilised can be any one from:
- Electric heaters
- Electric ovens
- Electric hobs
- Toasters
- Kettles
- Filament bulbs
- Fuses
State the type of current supplied by mains electricity.
Mains electricity supplies an alternating current (a.c.).
What device supplies a direct current (d.c.) to an electrical circuit?
A battery or cell supplies a direct current to an electrical circuit.
Define direct current.
Direct current is a steady current, constantly flowing in one direction through a circuit, from positive to negative.
True or False?
The potential difference across a cell in a d.c. circuit travels in two directions only.
False.
The potential difference across a cell in a d.c. circuit travels in one direction only.
Define an alternating current (a.c.).
An alternating current is a current that continuously changes its direction, going back and forth around a circuit.
True or False?
An alternating current power supply has two different terminals, one positive and one negative.
False.
An alternating current power supply has two identical terminals that change from positive to negative and back again.
State the frequency of mains electricity in the UK.
The frequency of mains electricity in the UK is 50 Hz.
What type of current is shown in the graph?
The graph shows direct current (d.c.).
Draw a current-time graph for alternating current (a.c.).
A current-time graph for alternating current (a.c.) looks like this:
State the type of current used by a lamp plugged into a domestic plug socket.
Alternating current is used by a lamp plugged into a domestic plug socket.

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