P3 Flashcards
What happens when two insulators are rubbed together?
Electrons are transferred from one insulator to another
The positive charges don’t move so one insulator ends up with extra electrons and one with not enough
What are sparks?
Flows of charge, or a current through the air
Where are electrical fields from?
Around charged objects or particles
If another object is in the field it will either be attracted or repelled
How do you know the strength of a magnetic field?
Stronger field = field lines closer together
Field line always go to the positive charge
What is current?
Rate of flow of charged particles, or charge
How do you calculate charge flow?
Change flow (C) = current x time
What is potential difference?
Measured in volts
Push needed to get the charges from one point to another (make a current flow)
What is the equation for energy transferred?
Energy transferred = p.d x charge
What is a series circuit?
Only has one loop
Current is the same everywhere
P.d divides proportional to the resistors
Where do the voltmeter and ammeter go in a series circuit?
Ammeter goes in series
Voltmeter connected to both sides if a component and parallel
What happens in a parallel circuit?
Has multiple loops
Each loops works independently
The current at different points will add to the current near the battery
P.d is the same at each path
What does current depend on?
Potential difference of the cell or the battery
Resistance of components
What is resistance?
Measured in ohms
Opposition to current
Tells the circuit how much current flows for a given p.d.
Insulators have a high resistance (no current flows)
What is the equation for resistance?
Resistance = p.d (V)/current(I)
How to find net resistance?
1/R1 + 1/R2 = 1/net resistance
Do reciprocal
