P4.4 Component characteristics Flashcards
1
Q
Why does the resistance of any metal increases as temperature increase?
A
Atoms in the metal vibrate more as temperature increases - so they resist the passage of the electrons through the filament more
2
Q
Why does a filament light bulb fail?
A
Resistance is low when the bulb is off - when it is switched on a big current passes through it - so burns the filament
3
Q
What is a thermistor?
A
Temperature dependent resistor - resistance decreases if its temperature increases
4
Q
What is a LDR?
A
Light dependent resistor - the resistance decreases if the light intensity increases
