Electricity Flashcards
To learn the content for the electricity section of the course
What is current?
The charge transferred per second
What is meant by the potential difference (voltage) of a supply?
It is the number of Joules of energy given to each coulomb of charge passing through the cell
Which device measures current?
Ammeter
Which device measures voltage?
Voltmeter
Which device measures resistance?
Ohmmeter
What is the symbol for an ammeter?
Circle with an A in it.
What is the symbol for a voltmeter?
Circle with a V in it
What is the symbol for an Ohmmeter?
Circle with an Omega in it
How should an ammeter be connected to measure the current in a component?
It should be connected in series with the component
How should a voltmeter be connected to measure the voltage across a component?
It should be connected across the component
How can you identify a series circuit?
It is a circuit with only one path round it.
What is the rule for current in a series circuit?
The current is the same everywhere
I1=I2=I3
What is the rule for voltages in a series circuit?
The voltage across each component added together is equal to the supply voltage.
Vs=V1+V2+ …
What happens if you unscrew one of the lamps in the circuit below? Why?
The other lamps go out. There is a break in the circuit and the current does not have a complete route to the battery.
If you heat a conductor, what happens to it’s resistance?
It increases
How can a parallel circuit be identified?
It is a circuit with more than one path round it.
What is the rule for current in a parallel circuit?
The supply current is equal to the current in each branch added together.
IS = I1+I2+…
What is the rule for voltages in a parallel circuit?
The voltage across each branch is equal to the supply voltage.
VS=V1=V2= ….
Which circuit component is represented by the following diagram?
Cell
Which circuit component is represented by the following diagram?
Battery
Which circuit component is represented by the following diagram?
Switch
Which circuit component is represented by the following diagram?
Lamp
Which circuit component is represented by the following diagram?
Motor
Which circuit component is represented by the following diagram?
Loudspeaker
Which circuit component is represented by the following diagram?
Resistor
Which circuit component is represented by the following diagram?
Variable Resistor
Which circuit component is represented by the following diagram?
Thermistor
Which circuit component is represented by the following diagram?
Light Dependent Resistor
Which circuit component is represented by the following diagram?
Fuse
Which circuit component is represented by the following diagram?
Diode
Which circuit component is represented by the following diagram?
Light Emitting Diode
Which circuit component is represented by the following diagram?
Photovoltaic cell / solar cell
Which circuit component is represented by the following diagram?
Microphone
What is the energy chage in a battery?
Chemical to electrical
What is the energy change in a lamp?
Electrical to light (+ heat)
What is the energy change in a motor?
Electrical to kinetic
What is the energy change in a loudspeaker?
Electrical to sound
What is the energy change in a buzzer?
Electrical to sound
What is the energy change in an LED?
Electrical to light
What is the energy change in a photovoltaic cell?
Light to electrical
What is the energy change in a microphone?
Sound to electrical
What happens if you increase the resistance in a circuit?
The current will decrease
State two place a variable resistor can be used.
Light dimmer switch sped control on Scalextric cars volume control on a radio
State a device that can be used in a temperature sensor
Thermistor
State a device that can be used in a light sensor
LDR
What is a thermistor?
A resistor whose resistance changes with changes in temperature