Combined Physics - P2 Electricity Flashcards
What is the circuit symbol for an open switch?

What is the circuit symbol for a closed switch?

What is the circuit symbol for a cell?

What is the circuit symbol for a battery?

What is the circuit symbol for a diode?

What is the circuit symbol for a resistor?

What is the circuit symbol for a variable resistor?

What is the circuit symbol for an LED?

What is the circuit symbol for a lamp?

What is the circuit symbol for a fuse?

What is the circuit symbol for a voltmeter?

What is the circuit symbol for an ammeter?

What is the circuit symbol for a thermistor?

What is the circuit symbol for an LDR?

What is current?
The rate of flow of charge
What component is the IV graph in the image for?

A Resistor (at constant temperature)
What type of circuit is shown in the image?

Series circuit
What component is the IV graph in the image for?
A diode
What type of circuit is shown in the image?

Parallel circuit
What component is the IV graph in the image for?
A filament lamp

What happens to the resistance of a thermistor as temperature increases?
Resistance decreases
What happens to the resistance of an LDR as light increases?
Resistance decreases
What’s the difference between direct current and alternating current?
- Direct current flows in only one direction.
- Alternating current constantly changes direction.
What is the rule for current in a series circuit?
Current is the same everywhere in the circuit
Name the electrical component used in thermostats.
Thermistor
Where are LDRs commonly found?
LDRs are used as automatic night lights
What is the National Grid?
A system of cables and transformers
What is the rule for potential difference in a series circuit?
Potential difference is shared between components.
Where should you place an ammeter to measure current through a component?
The ammeter should be placed in series with the component.
What is the rule for potential difference in a parallel circuit?
It is the same in each branch.
Where should you place a voltmeter to measure potential difference across a component?
The voltmeter should be placed parallel to the component.
What type of electricity supply is a battery?
Direct current (DC)
What is the total resistance of the three resistors in series?

25 Ω
What is the rule for current in a parallel circuit?
Current is shared between the branches.
What type of electricity supply is mains electricity?
Alternating current (AC)
Name the equipment used to measure potential difference.
Voltmeter
What is the frequency of mains electricity?
50 Hz
Name the three wires in a three-core cable and say what colour they are.
- Live wire (brown)
- Neutral wire (blue)
- Earth wire (green / yellow striped)
What is the function of the neutral wire (blue)
Completes the circuit carrying current away (0 V)
What is the potential difference of mains electricity?
230 V
What is the function of the live wire (brown)?
Provides the alternating potential difference (230V)
What is the function of the Earth wire (green / yellow)?
Acts as a safety device, stopping the appliance casing from becoming live (0 V)
What two things determine how much energy is transferred by an electrical appliance.
- How long the appliance is on for
- The power rating of the appliance
Describe how electricity is transmitted across the National Grid to make it as efficient as possible.
- High potential difference
- Low current
- Which decreases energy lost by heating the wires/surrounding
How are step-down transformers used within the National Grid?
Step-down transformers bring the 400,000 V of the National Grid down to 230 V for use in the home.
Name the equipment used to measure current.
Ammeter
How are step-up transformers used within the National Grid?
Step-up transformers increase the potential difference of the National Grid to 400,000 V
Sketch a graph to show how light intensity affects resistance in an LDR.

Sketch a graph to show how temperature affects resistance in a thermistor.
