Electricity Flashcards
What is current?
The amount of charge flowing per second
-measured in amps(A)
What is resistance?
The resistance of current flow
What is an LDR and how does it work?
A semi-conductor whose resistance decreases as the intensity of light shining on it increases
What are some common applications of LDR’s?
automatic street lighting
burglar alarms
What is a thermistor and how does it work?
A semi-conductor that has a Negative Temperature Co-efficient (NTC), therefore resistance decreases as temperature increases
Why does the resistance decrease after the temperature increases in a thermistor?
As the temp rises, more electrons become free to move within the semi-conductor material, increasing conductivity and thus decreasing resistance
What are some common applications of thermistors?
Ovens
Refrigerators
Air cons
What is needed for a current to flow?
A closed circuit with a conductor [wire] that connects the two oppositely charged terminals of a source [such as a cell or battery]
What is conventional current?
What is potential difference?
It’s the ‘push’ that drives the current
-provides energy to each electron
-measured in volts
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How does potential difference work?
