Controlling And Using Electric Currants Flashcards
How can currant be measured
By placing an ammeter into a series circuit that you want to measure the currant
Does currant decrease in a circuit after it passes through something such as a lightbulb
No as they aren’t used up so the flow of electrons (currant) in a series circuits will be the same anywhere
How can currant be changed
By increasing the potential difference of the cell (voltage). Greater the voltage the greater the currant
What is 1 volt equal to
1 joule per coulomb
E.g. 20C (charge) goes through a lightbulb. The potential difference across the bulb is 5V. The enger transferred = 4J joules as 20/5 = 4
How is potential difference measured
Potential difference = joues into component - joules out of component
What is resistance in a circuit
How easy or hard it is for currant to flow in the circuit and is measured in ohms
The higher the resistance the smaller the currant
What is a diode
A component that can be used in a circuit to control direction of currant, currant will only flow if potential difference is applied in the correct direction
How can a filament lamp cause resistance in a circuit
The higher the potential difference, the hotter the filament becomes meaning resistance increases
What is an LDR
Light dependent resistor. The darker it is, the higher the resistance
What is a thermistor
A resistor that has high resistance when cold and becomes less the hotter it becomes
What happens to a resistor when more potential difference is applied
It becomes hotter as it has more energy transferred into it
Name 2 appliances that benefit from the heating effect on resistors and 2 appliances that it has a negative effect on
Electric fire and kettle
Motors and light bulb
