Electric circuits Flashcards
Explain how an electric current flows around a circuit
- An electric current is a flow of charge
- It can only flow if the circuit is complete
- The moving charges are electrons which are negatively charged
- The current in a circuit is always the same it is never used up
What is another name for voltage?
potential difference
What is another name for potential difference
voltage
Describe the job of a battery in a circuit?
The battery provides the voltage in the circuit which pushes the electrons around making a current flow
Combining batteries does what to the voltage in a circuit?
The voltages are combined
eg 2 x 12V batteries gives a voltage of 24V
What units are used for voltage
Volts (V)
Describe resistance in a circuit
Resistance is anything which slows down the flow of current
What is a component in a circuit
Anything you put into it
eg a lamp
How does the number of components in a circuit affect the current?
The more components the higher the resistance and the slower the current
Will a good conductor of electricity have high or low resistance?
The better the conductor the lower the resistance.
What type of energy does a battery contain?
Chemical energy
Describe how batteries transfer energy to other components
- The chemical energy in the battery is transformed into electrical energy
- The electrical energy is transferred to the components
- The component, such as bulbs transform the electrical energy into other forms such as light and heat
Explain why an ammeter may be connected to a circuit
- An ammeter measures the current flowing through a circuit in amps (A)
- You put an ammeter into a circuit in line with the other components, it doesnt need it’s own loop
- The current through the ammeter is the same as the other components in the circuit such as a bulb.
Explain why an voltmeter may be connected to a circuit
- A voltmeter measures voltage in Volts (V)
You put a voltmeter into it’s own loop below the component you want to know the voltage of eg a bulb
State the component
Electromagnet
State the component
Reed switch
State the component
simple on off switch
State the component
Ammeter
State the component
Variable resistor
State the component
Resistor
State the component
Battery
State the component
Push button switch
State the component
LED- light emitting diode
State the component
Lamp
State the component
Light dependent resistor
State the component
Semi conductor diode
State the component
Junction of conductors
State the component
fuse
What is the role of the component?
Breaks the circuit if the current is too high
What is the role of the component?
reduces current flowing through the circuit
What is the role of the component?
switch controlled by a magnetic field
State the component
Relay
State the component
Terminals
State the component
Buzzer
What is the role of the component?
switch controlled by an electromagnet
What is the role of the component?
Coil of wire with magnetic field
What is the role of the component?
only lets the current flow in one direction
What is the role of the component?
Resistance decreases when light is shone onto it
What is the role of the component?
Lights up when current it passed through
What is the difference between series and parallel circuits?
In series circuits the electricity can only flow one way whereas in parallel circuits it can take different routes
What are the characteristics of a series circuit
- The current is the same everywhere on the circuit
- The voltages across the components add up to make the voltage of the battery or cell
- The current only takes one route through all of the components
What are the characteristics of a parallel circuit?
The current has a choice of different routes
The current splits between each of the routes
The voltage across each bulb is the same
What type of circuit is this?
Series circuit
Give the equation for the voltages on this series circuit
Vs = V1 + V2
What will the ammeters show about the current on this series circuit?
I = I1 = I2
They will all read the same
What type of circuit is this?
Parallel
Which ammeter values will be the same?
A1 and A5
What is the relationship between A1 and A2,3 and 4
A1 = A2 + A3 + A4
This is a picture of an AND circuit
Explain what needs to happen to light the bulb
Switch 1 AND switch 2 both need to be closed to complete the circuit
This is a gif of a parallel OR circuit
Explain what needs to happen to light the bulb
Switch 1 OR switch 2 need to be closed to complete the circuit
