Current Elecrity Flashcards
If the insulating material becomes gains electrons…
It becomes Negatively charged eg polythene rod
If the insulating material loses electrons…
It becomes positively charged eg Perspex rod
Like charges repel unlike charges…
Attract
What is a battery?
2 or more cells connected together
What is electric current?
The rate of the flow of charge (electrons)
What are ammeters always connected in?
Series
What are voltmeters always connected in?
Parallel
1 milliamperes = …..
0.001 A
What is potential difference?
Work done per coulomb of charge
What does ohms law state?
The current through a resistor (at a constant temperature) is directly proportional to the potential difference (voltage) across a resistor
What does reversing the current through a component do to the PD?
The PD reverses
What happens to the resistance of a filament lamp as the temperature increases?
As the temperature increases the resistance increases this is because as the temperature increases the PD increases so the metal’s delocalised electrons collide with the metal ions more frequently restricting theft
How do certain materials become charged?
When rubbed together electrons are transferred from one material to the other
