SP6d More about Resistance Flashcards
Is current a dependent or independent variable?
.independent variable
.variable resistor is used to change the current flowing through the component
Is voltage a dependent or independent variable?
.dependent variable
.voltmeter is used to measure the voltage across the component
What are characteristic graphs used for?
they can be used to predict the amount of current drawn by an electrical component when a certain potential difference is across it.
What is the filament of a lamp?
.a coil of fine wire inside the glass
.when the lamp is turned on the filament heats up and glows white hot
What is a diode, what is it made of and what does it allow?
.one way-switch
.made from semi-conductor materials
.allows current to flow easily in one direction, but not in the opposite directon
Why does current increase when you increase the voltage?
because more energy is being transferred to electrons.
What is a light dependent resistor?
a type of variable resistor.
Describe the relationship between light falling on an LDR and its resistance.
the brighter the light falling on an LDR, the smaller its resistance.
What is a thermistor?
a type of variable resistor.
Describe the relationship between temperature and resitance.
the higher the temperature, the small the resistance.
What do diodes do?
protect sensitive electronic devices from too much voltage.
Where are light-emitting diodes found and why?
indicator lights and in all lighting as they use less electricity than ordinary lighting.
