Resistors Flashcards
What is a resistor?
Anything which can reduce the flow of current in a circuit
What does ohms law say?
As current increases, p.d also increases (given that temperature in the circuit stays the same)
In a Current and p.d graph which one is the x and y axis?
Y=Current X=Voltage
Does a filament bulb follow ohm’s law and what does the I/V graph look like?
No, it increase steeply and then starts decreasing the rate at which is increasing making a gentler slope
How does resistance in a bulb increasing affect the current?
When current increases its temperature increases too
Atoms vibrate more and more in the filament bulb
This makes it harder for the electric charge to get through
What is a normal diode in terms of bias?
Forward biased
What is a flipped diode in terms of bias?
Reverse biased
How does a graph of I/V look in a diode look like?
It’s zero until a little after hitting origin where it spikes up
How does the resistance in a thermistor change and how does it affect it?
By temperature, as resistance decreases temperature increases (inversely proportional)
What are some uses of thermistors?
Fire alarms, thermostats
How does resistance change in a Light Dependant Resistor and how?
Dark=High resistance bright=low resistance (inversely proportional)
Uses of LDR?
Automatic lights, automatic camera flashes
Which measures is connected in series and which one in parallel?
Ammeter=series voltmeter=parallel
