Resistance Flashcards
What is the formula connecting pd, current and resistance?
V = IR
V = voltage (pd)
I = Current
R = resistance
What are pd and resistance measured in?
V = v(olts)
Resistance = Ohms (Ω)
What can happen with some components as the current through them is changed?
the resistance of the component changes as well. (e.g. a filament or diode)
What happens to the resistance in an ohmic conductor when the current changes?
The resistance doesn’t change.
What happens when an electrical charge flows through a filament lamp?
When an electrical charge flows through a filament lamp it transfers some energy to the thermal energy store of the filament which is designed to heat up. Resistance increases with temp - as the current increases the filament lamp heats up and the resistance increases.
How does current affect resistance in a diode?
The resistance depends on the direction of the current. In one direction the current can flow thru with very little resistance but in the other direction, the resistance will be very high.
