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5 Electricity - Coggle Diagram
5 Electricity
Direct current circuits
- At any junction in a circuit, the total current leaving the junction is equal to the total current entering the junction
- current is the same throughout a series circuit
- the pd across parallel circuits is the same
- the pd in a series circuit is shared across the components
- for any complete loop in a circuit the sum of the emfs round the loop is equal is equal to the potential difference drops round the loop
RESISTANCE
- resistance in a parallel circuit is smaller than the smallest resistance
- total resistance in a series circuit is the addition of all the resistance added together
:pencil2: Resistance heating= heating effect on an electric current due to the resistance of a component
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Potential divider = 2 or more resisitors in series which consists of each other and a source of fixed potential difference
:champagne: A Variable resistor can be supplied by a battery by having a source pd is connected to a fixed length of the uniform wire and a sliding contact of the wire can then move along the wire
:!: sensor circuit produces an output pd which changes as a result of change of a physical variable such as temperature or light intensity
electric current
Current and charge
:red_flag: electric current = the rate of flow of charge
:red_flag: charge flow: Q = It
:red_flag: charge carriers = charged particles that create current
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Resistance
- resistance is caused by the repeated collisions between the charge carriers and the material increasing the difficulty of making current pass through the component
- ohms law can be used when the pd is proportional to the current giving that the temperature is kept constant
- :!: super conductor= wire of a material has zero resistivity at and below the critical temperature
characteristics
- in a filament lamp as the current increases the resistance increases also with a big increase in potential difference there is a small current is produced
- a diode is an appliance that only lets current flow in one direction
- thermistors are used in thermostats this is because as temperature increases resistance decreases
